diff --git a/CHANGELOG.md b/CHANGELOG.md
index 649db9dd..5c51bbc3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Features
 
 - 数据库迁移自动填充 NULL 值为模型默认值
+- Passkey 登录支持无用户名模式（可发现凭证）
 
 ### Fixes
 
@@ -18,6 +19,7 @@
 - 重新设计搜索面板，新增模态框和过滤系统
 - 重新设计登录面板，采用现代毛玻璃风格
 - 日志页面新增日志级别过滤功能
+- Passkey 登录支持无用户名模式（可发现凭证）
 
 ### Fixes
 
diff --git a/backend/src/module/api/passkey.py b/backend/src/module/api/passkey.py
index 0275a9a2..cb90d1c0 100644
--- a/backend/src/module/api/passkey.py
+++ b/backend/src/module/api/passkey.py
@@ -160,9 +160,22 @@ async def get_passkey_login_options(
     """
     生成 Passkey 登录选项（challenge）
     前端先调用此接口，再调用 navigator.credentials.get()
+
+    如果提供 username，返回该用户的 passkey 列表（allowCredentials）
+    如果不提供 username，返回可发现凭证选项（浏览器显示所有可用 passkey）
     """
     webauthn = _get_webauthn_from_request(request)
 
+    # Discoverable credentials mode (no username)
+    if not auth_data.username:
+        try:
+            options = webauthn.generate_discoverable_authentication_options()
+            return options
+        except Exception as e:
+            logger.error(f"Failed to generate discoverable login options: {e}")
+            raise HTTPException(status_code=500, detail=str(e))
+
+    # Username-based mode
     async with async_session_factory() as session:
         try:
             # Get user
@@ -201,6 +214,9 @@ async def login_with_passkey(
 ):
     """
     使用 Passkey 登录（替代密码登录）
+
+    如果提供 username，验证 passkey 属于该用户
+    如果不提供 username（可发现凭证模式），从 credential 中提取用户信息
     """
     webauthn = _get_webauthn_from_request(request)
 
@@ -208,12 +224,17 @@ async def login_with_passkey(
     resp = await strategy.authenticate(auth_data.username, auth_data.credential)
 
     if resp.status:
+        # Get username from response (may be discovered from credential)
+        username = resp.data.get("username") if resp.data else auth_data.username
+        if not username:
+            raise HTTPException(status_code=500, detail="Failed to determine username")
+
         token = create_access_token(
-            data={"sub": auth_data.username}, expires_delta=timedelta(days=1)
+            data={"sub": username}, expires_delta=timedelta(days=1)
         )
         response.set_cookie(key="token", value=token, httponly=True, max_age=86400)
-        if auth_data.username not in active_user:
-            active_user.append(auth_data.username)
+        if username not in active_user:
+            active_user.append(username)
         return {"access_token": token, "token_type": "bearer"}
 
     raise HTTPException(status_code=resp.status_code, detail=resp.msg_en)
diff --git a/backend/src/module/models/passkey.py b/backend/src/module/models/passkey.py
index 0cfe047e..c693da96 100644
--- a/backend/src/module/models/passkey.py
+++ b/backend/src/module/models/passkey.py
@@ -65,11 +65,11 @@ class PasskeyDelete(BaseModel):
 class PasskeyAuthStart(BaseModel):
     """Passkey 认证开始请求"""
 
-    username: str
+    username: Optional[str] = None  # Optional for discoverable credentials
 
 
 class PasskeyAuthFinish(BaseModel):
     """Passkey 认证完成请求"""
 
-    username: str
+    username: Optional[str] = None  # Optional for discoverable credentials
     credential: dict
diff --git a/backend/src/module/security/auth_strategy.py b/backend/src/module/security/auth_strategy.py
index 4b17a24c..cc8edf3c 100644
--- a/backend/src/module/security/auth_strategy.py
+++ b/backend/src/module/security/auth_strategy.py
@@ -16,12 +16,14 @@ class AuthStrategy(ABC):
     """认证策略基类"""
 
     @abstractmethod
-    async def authenticate(self, username: str, credential: dict) -> ResponseModel:
+    async def authenticate(
+        self, username: str | None, credential: dict
+    ) -> ResponseModel:
         """
         执行认证
 
         Args:
-            username: 用户名
+            username: 用户名（可选，用于可发现凭证模式）
             credential: 认证凭证（密码或 WebAuthn 响应）
 
         Returns:
@@ -36,41 +38,28 @@ class PasskeyAuthStrategy(AuthStrategy):
     def __init__(self, webauthn_service):
         self.webauthn_service = webauthn_service
 
-    async def authenticate(self, username: str, credential: dict) -> ResponseModel:
-        """使用 WebAuthn Passkey 认证"""
-        async with async_session_factory() as session:
-            # 1. 查找用户
-            try:
-                result = await session.execute(
-                    select(User).where(User.username == username)
-                )
-                user = result.scalar_one_or_none()
-                if not user:
-                    raise ValueError("User not found")
-            except ValueError:
-                return ResponseModel(
-                    status_code=401,
-                    status=False,
-                    msg_en="User not found",
-                    msg_zh="用户不存在",
-                )
+    async def authenticate(
+        self, username: str | None, credential: dict
+    ) -> ResponseModel:
+        """
+        使用 WebAuthn Passkey 认证
 
-            # 2. 提取 credential_id 并查找对应的 passkey
+        Args:
+            username: 用户名（可选）。如果为 None，使用可发现凭证模式
+            credential: WebAuthn 凭证响应
+        """
+        async with async_session_factory() as session:
+            passkey_db = PasskeyDatabase(session)
+
+            # 1. 提取 credential_id
             try:
                 raw_id = credential.get("rawId")
                 if not raw_id:
                     raise ValueError("Missing credential ID")
 
-                # 将 rawId 从 base64url 转换为标准格式
                 credential_id_str = self.webauthn_service.base64url_encode(
                     self.webauthn_service.base64url_decode(raw_id)
                 )
-
-                passkey_db = PasskeyDatabase(session)
-                passkey = await passkey_db.get_passkey_by_credential_id(credential_id_str)
-                if not passkey or passkey.user_id != user.id:
-                    raise ValueError("Passkey not found or not owned by user")
-
             except Exception:
                 return ResponseModel(
                     status_code=401,
@@ -79,13 +68,54 @@ class PasskeyAuthStrategy(AuthStrategy):
                     msg_zh="Passkey 凭证无效",
                 )
 
-            # 3. 验证 WebAuthn 签名
-            try:
-                new_sign_count = self.webauthn_service.verify_authentication(
-                    username, credential, passkey
+            # 2. 查找 passkey
+            passkey = await passkey_db.get_passkey_by_credential_id(credential_id_str)
+            if not passkey:
+                return ResponseModel(
+                    status_code=401,
+                    status=False,
+                    msg_en="Passkey not found",
+                    msg_zh="未找到 Passkey",
                 )
 
-                # 4. 更新使用记录
+            # 3. 获取用户
+            result = await session.execute(
+                select(User).where(User.id == passkey.user_id)
+            )
+            user = result.scalar_one_or_none()
+            if not user:
+                return ResponseModel(
+                    status_code=401,
+                    status=False,
+                    msg_en="User not found",
+                    msg_zh="用户不存在",
+                )
+
+            # 4. 如果提供了 username，验证一致性
+            if username and user.username != username:
+                return ResponseModel(
+                    status_code=401,
+                    status=False,
+                    msg_en="Passkey does not belong to specified user",
+                    msg_zh="Passkey 不属于指定用户",
+                )
+
+            # 5. 验证 WebAuthn 签名
+            try:
+                if username:
+                    # Username-based mode
+                    new_sign_count = self.webauthn_service.verify_authentication(
+                        username, credential, passkey
+                    )
+                else:
+                    # Discoverable credentials mode
+                    new_sign_count = (
+                        self.webauthn_service.verify_discoverable_authentication(
+                            credential, passkey
+                        )
+                    )
+
+                # 6. 更新使用记录
                 await passkey_db.update_passkey_usage(passkey, new_sign_count)
 
                 return ResponseModel(
@@ -93,6 +123,7 @@ class PasskeyAuthStrategy(AuthStrategy):
                     status=True,
                     msg_en="Login successfully with passkey",
                     msg_zh="通过 Passkey 登录成功",
+                    data={"username": user.username},
                 )
 
             except ValueError as e:
diff --git a/backend/src/module/security/webauthn.py b/backend/src/module/security/webauthn.py
index c7228fc1..5a7f1689 100644
--- a/backend/src/module/security/webauthn.py
+++ b/backend/src/module/security/webauthn.py
@@ -81,7 +81,7 @@ class WebAuthnService:
             user_display_name=username,
             exclude_credentials=exclude_credentials if exclude_credentials else None,
             authenticator_selection=AuthenticatorSelectionCriteria(
-                resident_key=ResidentKeyRequirement.PREFERRED,
+                resident_key=ResidentKeyRequirement.REQUIRED,  # Required for usernameless login
                 user_verification=UserVerificationRequirement.PREFERRED,
             ),
             supported_pub_key_algs=[
@@ -191,6 +191,26 @@ class WebAuthnService:
 
         return json.loads(options_to_json(options))
 
+    def generate_discoverable_authentication_options(self) -> dict:
+        """
+        生成可发现凭证的认证选项（无需用户名）
+
+        Returns:
+            JSON-serializable authentication options without allowCredentials
+        """
+        options = generate_authentication_options(
+            rp_id=self.rp_id,
+            allow_credentials=None,  # Empty = discoverable credentials mode
+            user_verification=UserVerificationRequirement.PREFERRED,
+        )
+
+        # Store challenge with a unique key for discoverable auth
+        challenge_key = f"auth_discoverable_{self.base64url_encode(options.challenge)[:16]}"
+        self._challenges[challenge_key] = options.challenge
+        logger.debug("Generated discoverable authentication challenge")
+
+        return json.loads(options_to_json(options))
+
     def verify_authentication(
         self, username: str, credential: dict, passkey: Passkey
     ) -> int:
@@ -236,6 +256,56 @@ class WebAuthnService:
             # 清理 challenge（无论成功或失败都清理，防止重放攻击）
             self._challenges.pop(challenge_key, None)
 
+    def verify_discoverable_authentication(
+        self, credential: dict, passkey: Passkey
+    ) -> int:
+        """
+        验证可发现凭证的认证响应（无需用户名）
+
+        Args:
+            credential: 来自前端的 credential 响应
+            passkey: 通过 credential_id 查找到的 Passkey 对象
+
+        Returns:
+            新的 sign_count
+
+        Raises:
+            ValueError: 验证失败
+        """
+        # Find the challenge by checking all discoverable challenges
+        expected_challenge = None
+        challenge_key = None
+        for key, challenge in list(self._challenges.items()):
+            if key.startswith("auth_discoverable_"):
+                expected_challenge = challenge
+                challenge_key = key
+                break
+
+        if not expected_challenge:
+            raise ValueError("Challenge not found or expired")
+
+        try:
+            credential_public_key = base64.b64decode(passkey.public_key)
+
+            verification = verify_authentication_response(
+                credential=credential,
+                expected_challenge=expected_challenge,
+                expected_rp_id=self.rp_id,
+                expected_origin=self.origin,
+                credential_public_key=credential_public_key,
+                credential_current_sign_count=passkey.sign_count,
+            )
+
+            logger.info("Successfully verified discoverable authentication")
+            return verification.new_sign_count
+
+        except Exception as e:
+            logger.error(f"Discoverable authentication verification failed: {e}")
+            raise ValueError(f"Invalid authentication response: {str(e)}")
+        finally:
+            if challenge_key:
+                self._challenges.pop(challenge_key, None)
+
     # ============ 辅助方法 ============
 
     def _parse_transports(
diff --git a/webui/src/hooks/usePasskey.ts b/webui/src/hooks/usePasskey.ts
index 6ea74404..e9933888 100644
--- a/webui/src/hooks/usePasskey.ts
+++ b/webui/src/hooks/usePasskey.ts
@@ -1,9 +1,9 @@
 import { createSharedComposable } from '@vueuse/core';
 import { apiPasskey } from '@/api/passkey';
 import {
+  isWebAuthnSupported,
   registerPasskey,
   loginWithPasskey as webauthnLogin,
-  isWebAuthnSupported,
 } from '@/services/webauthn';
 import type { PasskeyItem } from '#/passkey';
 
@@ -56,7 +56,7 @@ export const usePasskey = createSharedComposable(() => {
   }
 
   // 使用 Passkey 登录
-  async function loginWithPasskey(username: string): Promise<boolean> {
+  async function loginWithPasskey(username?: string): Promise<boolean> {
     try {
       await webauthnLogin(username);
       isLoggedIn.value = true;
diff --git a/webui/src/services/webauthn.ts b/webui/src/services/webauthn.ts
index 5fcba4c1..fef795b8 100644
--- a/webui/src/services/webauthn.ts
+++ b/webui/src/services/webauthn.ts
@@ -108,17 +108,20 @@ export async function registerPasskey(deviceName: string): Promise<void> {
 
 /**
  * 使用 Passkey 登录
- * @param username 用户名
+ * @param username 用户名（可选，不提供时使用可发现凭证模式）
  */
-export async function loginWithPasskey(username: string): Promise<void> {
+export async function loginWithPasskey(username?: string): Promise<void> {
   // 1. 获取认证选项
-  const options = await apiPasskey.getLoginOptions({ username });
+  const options = await apiPasskey.getLoginOptions(
+    username ? { username } : {}
+  );
 
   // 2. 转换选项
   const getOptions: PublicKeyCredentialRequestOptions = {
     challenge: base64UrlToBuffer(options.challenge),
     timeout: options.timeout || 60000,
     rpId: options.rpId,
+    // allowCredentials is undefined for discoverable credentials mode
     allowCredentials: options.allowCredentials?.map((cred) => ({
       type: cred.type as PublicKeyCredentialType,
       id: base64UrlToBuffer(cred.id),
@@ -154,7 +157,7 @@ export async function loginWithPasskey(username: string): Promise<void> {
 
   // 5. 提交到后端验证并登录
   await apiPasskey.loginWithPasskey({
-    username,
+    ...(username && { username }),
     credential: assertionResponse,
   });
 }
diff --git a/webui/types/passkey.ts b/webui/types/passkey.ts
index 5368db58..dc8ee5c3 100644
--- a/webui/types/passkey.ts
+++ b/webui/types/passkey.ts
@@ -60,11 +60,11 @@ export interface PasskeyDeleteRequest {
 
 // 认证开始请求
 export interface PasskeyAuthStartRequest {
-  username: string;
+  username?: string; // Optional for discoverable credentials
 }
 
 // 认证完成请求
 export interface PasskeyAuthFinishRequest {
-  username: string;
+  username?: string; // Optional for discoverable credentials
   credential: unknown;
 }