diff --git a/.github/workflows/build-v3.yml b/.github/workflows/build-v3.yml
index 0d7611e99..bede1330e 100644
--- a/.github/workflows/build-v3.yml
+++ b/.github/workflows/build-v3.yml
@@ -12,7 +12,49 @@ permissions:
   packages: write
 
 jobs:
+  release-gate:
+    runs-on: ubuntu-latest
+    outputs:
+      publish: ${{ steps.detect.outputs.publish }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
+
+      - name: Detect version change
+        id: detect
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+          BEFORE_SHA: ${{ github.event.before }}
+        run: |
+          set -euo pipefail
+          if [ "$EVENT_NAME" = workflow_dispatch ]; then
+            echo "publish=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          versions() {
+            sed -nE "s/^(APP_VERSION|FRONTEND_VERSION)[[:space:]]*=[[:space:]]*'([^']+)'[[:space:]]*$/\1=\2/p" | sort
+          }
+          previous=$(git show "$BEFORE_SHA:version.py" | versions)
+          current=$(versions < version.py)
+          for value in APP_VERSION FRONTEND_VERSION; do
+            if ! printf '%s\n' "$previous" | grep -q "^${value}=" ||
+               ! printf '%s\n' "$current" | grep -q "^${value}="; then
+              echo "版本声明缺失: $value" >&2
+              exit 1
+            fi
+          done
+          if [ "$previous" = "$current" ]; then
+            echo "publish=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "publish=true" >> "$GITHUB_OUTPUT"
+          fi
+
   Docker-build:
+    needs: release-gate
+    if: needs.release-gate.outputs.publish == 'true'
     runs-on: ubuntu-latest
     name: Build Docker Image
     steps:
diff --git a/docs/development-setup.md b/docs/development-setup.md
index b9818837d..d8e44df23 100644
--- a/docs/development-setup.md
+++ b/docs/development-setup.md
@@ -215,6 +215,8 @@ uvx --from pip-audit pip-audit \
 Docker 镜像直接基于官方基础镜像构建，只安装应用运行所需的系统依赖；不运行镜像漏洞扫描，
 也不为扫描结果刷新系统包、删除基础镜像自带工具或维护漏洞忽略清单。正式版和 Beta 均直接构建
 并发布标准版与 free-threaded 版的双架构镜像。应用锁定依赖仍按上述流程审计。
+`v3` 分支自动发布仅在 `version.py` 的 `APP_VERSION` 或 `FRONTEND_VERSION` 值发生变化时运行；
+只修改该文件的说明文字不会重建正式镜像。维护者仍可通过手动触发正式发布工作流重建当前版本。
 
 ### 6. Contributor 提交准备
 
diff --git a/tests/test_release_supply_chain.py b/tests/test_release_supply_chain.py
index cc6035b1f..01f813505 100644
--- a/tests/test_release_supply_chain.py
+++ b/tests/test_release_supply_chain.py
@@ -403,6 +403,52 @@ def test_publish_refreshes_base_and_preserves_build_cache() -> None:
     assert "scope=moviepilot-v3-standard-docker," in publish["cache-to"]
 
 
+def test_release_gate_only_publishes_changed_versions(tmp_path: Path) -> None:
+    """
+    自动发布只接受版本值变化，手动重建保留入口。
+    """
+    workflow = _load_workflow()
+    gate = workflow["jobs"]["release-gate"]
+    build = workflow["jobs"]["Docker-build"]
+    assert build["needs"] == "release-gate"
+    assert build["if"] == "needs.release-gate.outputs.publish == 'true'"
+
+    repo = tmp_path / "repo"
+    repo.mkdir()
+    subprocess.run(["git", "init", "-q", str(repo)], check=True)
+    version_file = repo / "version.py"
+    version_file.write_text(
+        "APP_VERSION = 'v3.1.6'\nFRONTEND_VERSION = 'v3.1.6'\n",
+        encoding="utf-8",
+    )
+    subprocess.run(["git", "-C", str(repo), "add", "version.py"], check=True)
+    subprocess.run(
+        ["git", "-C", str(repo), "-c", "user.name=Test", "-c", "user.email=test@example.com",
+         "commit", "-qm", "base"],
+        check=True,
+    )
+    before_sha = subprocess.check_output(
+        ["git", "-C", str(repo), "rev-parse", "HEAD"], text=True
+    ).strip()
+    command = next(step for step in gate["steps"] if step.get("id") == "detect")["run"]
+    output_file = tmp_path / "output"
+
+    def detect(event_name: str, content: str) -> str:
+        version_file.write_text(content, encoding="utf-8")
+        output_file.write_text("", encoding="utf-8")
+        subprocess.run(
+            ["bash", "-e", "-c", command], cwd=repo, check=True,
+            env={**os.environ, "EVENT_NAME": event_name, "BEFORE_SHA": before_sha,
+                 "GITHUB_OUTPUT": str(output_file)},
+        )
+        return output_file.read_text(encoding="utf-8").strip()
+
+    assert detect("push", "\"\"\"说明文字\"\"\"\nAPP_VERSION = 'v3.1.6'\nFRONTEND_VERSION = 'v3.1.6'\n") == "publish=false"
+    assert detect("push", "APP_VERSION = 'v3.1.7'\nFRONTEND_VERSION = 'v3.1.6'\n") == "publish=true"
+    assert detect("push", "APP_VERSION = 'v3.1.6'\nFRONTEND_VERSION = 'v3.1.7'\n") == "publish=true"
+    assert detect("workflow_dispatch", "APP_VERSION = 'v3.1.6'\nFRONTEND_VERSION = 'v3.1.6'\n") == "publish=true"
+
+
 def test_release_publishes_free_threaded_image_with_separate_metadata_and_cache() -> None:
     """
     free-threaded 发布必须使用 v3t 命名、参数和独立缓存。