diff --git a/src/commands/add.rs b/src/commands/add.rs
index fc032c1..8b31e12 100644
--- a/src/commands/add.rs
+++ b/src/commands/add.rs
@@ -5,7 +5,10 @@ use colored::Colorize;
 
 use crate::models::blob::Blob;
 use crate::models::index::{FileMetaData, Index};
-use crate::utils::util::{check_repo_exist, get_relative_path, get_working_dir, list_files};
+use crate::utils::util::{
+    check_repo_exist, get_working_dir, is_inside_repo, is_inside_workdir, list_files, to_workdir_relative_path,
+    ROOT_DIR,
+};
 
 // TODO: fatal: ../moj/app.py: '../moj/app.py' is outside repository at 'Git-Rust'
 pub fn add(files: Vec<String>, all: bool, mut update: bool) {
@@ -50,8 +53,18 @@ pub fn add(files: Vec<String>, all: bool, mut update: bool) {
 }
 
 fn add_a_file(file: &Path, index: &mut Index) {
-    let relative_path = get_relative_path(file, &get_working_dir().unwrap());
+    if !is_inside_workdir(file) {
+        //文件不在工作区内
+        println!("fatal: '{}' is outside repository at '{}'", file.display(), get_working_dir().unwrap().display());
+        return;
+    }
+    if is_inside_repo(file) {
+        //文件在.mit内
+        println!("fatal: '{}' is inside '{}' repo", file.display(), ROOT_DIR);
+        return;
+    }
 
+    let relative_path = to_workdir_relative_path(file);
     if !file.exists() {
         //文件被删除
         index.remove(file);
diff --git a/src/utils/util.rs b/src/utils/util.rs
index d2b8afa..a7b50d9 100644
--- a/src/utils/util.rs
+++ b/src/utils/util.rs
@@ -123,6 +123,26 @@ pub fn get_working_dir() -> Option<PathBuf> {
     }
 }
 
+/// 检查文件是否在dir内(包括子文件夹)， 若不存在则false
+pub fn is_inside_dir(file: &Path, dir: &Path) -> bool {
+    if file.exists() {
+        let file = get_absolute_path(file);
+        file.starts_with(dir)
+    } else {
+        false
+    }
+}
+
+/// 检查文件是否在工作区内， 若不存在则false
+pub fn is_inside_workdir(file: &Path) -> bool {
+    is_inside_dir(file, &get_working_dir().unwrap())
+}
+
+/// 检查文件是否在.mit内， 若不存在则false
+pub fn is_inside_repo(file: &Path) -> bool {
+    is_inside_dir(file, &get_storage_path().unwrap())
+}
+
 pub fn format_time(time: &std::time::SystemTime) -> String {
     let datetime: chrono::DateTime<chrono::Utc> = time.clone().into();
     datetime.format("%Y-%m-%d %H:%M:%S.%3f").to_string()
@@ -256,10 +276,21 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_is_inside_repo() {
+        setup_test_with_mit();
+        let path = Path::new("../Cargo.toml");
+        assert_eq!(is_inside_workdir(path), false);
+
+        let path = Path::new(".mit/HEAD");
+        assert_eq!(is_inside_workdir(path), true);
+    }
+
     #[test]
     fn test_format_time() {
         let time = std::time::SystemTime::now();
         let formatted_time = format_time(&time);
+        println!("{:?}", time);
         println!("{}", formatted_time);
     }