diff --git a/src/commands/restore.rs b/src/commands/restore.rs
index 86811d8..178ba94 100644
--- a/src/commands/restore.rs
+++ b/src/commands/restore.rs
@@ -67,7 +67,7 @@ pub fn restore_worktree(filter: Option<&Vec<PathBuf>>, target_blobs: &Vec<(PathB
     let mut file_paths = util::integrate_paths(&input_paths); //根据用户输入整合存在的文件（绝对路径）
     file_paths.extend(deleted_files); //已删除的文件
 
-    let index = Index::new();
+    let index = Index::get_instance();
     let store = store::Store::new();
 
     for path in &file_paths {
@@ -139,7 +139,6 @@ pub fn restore_index(filter: Option<&Vec<PathBuf>>, target_blobs: &Vec<(PathBuf,
             }
         }
     }
-    index.save();
 }
 /**
 对于工作区中的新文件，若已跟踪，则删除；若未跟踪，则保留<br>
@@ -227,7 +226,8 @@ mod test {
         test_util::ensure_no_file(&path);
         cmd::add(vec![], true, false); //add -A
         cmd::restore(vec![".".to_string()], Some("HEAD".to_string()), false, true);
-        assert!(Index::get_instance().is_empty());
+        let index = Index::get_instance();
+        assert!(index.get_tracked_files().is_empty());
     }
 
     #[test]
diff --git a/src/models/index.rs b/src/models/index.rs
index 368d3fa..2a691b6 100644
--- a/src/models/index.rs
+++ b/src/models/index.rs
@@ -55,7 +55,7 @@ pub struct Index {
 
 impl Index {
     /// 从index文件加载
-    pub fn new() -> Index {
+    fn new() -> Index {
         let mut index = Index::default();
         index.load();
         return index;
@@ -67,7 +67,7 @@ impl Index {
         unsafe { &mut INSTANCE }
     }
 
-    /// 重置index 从文件重新加载，主要用于测试，防止单例模式的影响
+    /// 重置index，主要用于测试，防止单例模式的影响
     pub fn reload() {
         let index = Index::get_instance();
         index.load();
@@ -224,14 +224,14 @@ mod tests {
     #[test]
     fn test_load() {
         test_util::setup_test_with_clean_mit();
-        let index = Index::new();
+        let index = Index::get_instance();
         println!("{:?}", index);
     }
 
     #[test]
     fn test_save() {
         test_util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let path = PathBuf::from("../mit_test_storage/.mit/HEAD"); //测试../相对路径的处理
         index.add(path.clone(), FileMetaData::new(&Blob::new(&path), &path));
 
diff --git a/src/models/tree.rs b/src/models/tree.rs
index 914d763..adefd84 100644
--- a/src/models/tree.rs
+++ b/src/models/tree.rs
@@ -165,7 +165,7 @@ mod test {
     #[test]
     fn test_new() {
         test_util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         for test_file in vec!["b.txt", "mit_src/a.txt", "test/test.txt"] {
             let test_file = PathBuf::from(test_file);
             test_util::ensure_test_file(&test_file, None);
@@ -181,7 +181,7 @@ mod test {
     #[test]
     fn test_load() {
         test_util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let test_files = vec!["b.txt", "mit_src/a.txt"];
         for test_file in test_files.clone() {
             let test_file = PathBuf::from(test_file);
@@ -201,7 +201,7 @@ mod test {
     #[test]
     fn test_get_recursive_file_entries() {
         test_util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let mut test_files = vec![PathBuf::from("b.txt"), PathBuf::from("mit_src/a.txt")];
         for test_file in test_files.clone() {
             test_util::ensure_test_file(&test_file, None);
@@ -229,7 +229,7 @@ mod test {
     #[test]
     fn test_get_recursive_blobs() {
         test_util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let test_files = vec!["b.txt", "mit_src/a.txt"];
         let mut test_blobs = vec![];
         for test_file in test_files.clone() {
diff --git a/src/utils/util.rs b/src/utils/util.rs
index f6e3950..6bcc9d4 100644
--- a/src/utils/util.rs
+++ b/src/utils/util.rs
@@ -9,12 +9,10 @@ use std::{
 use crate::models::{commit::Commit, object::Hash, tree::Tree, Index};
 
 pub const ROOT_DIR: &str = ".mit";
-
 #[cfg(test)]
 pub mod test_util {
-    use super::*;
-
     pub const TEST_DIR: &str = "mit_test_storage"; // 执行测试的储存库
+    use super::*;
     /* tools for test */
     fn find_cargo_dir() -> PathBuf {
         let cargo_path = std::env::var("CARGO_MANIFEST_DIR");
@@ -37,26 +35,33 @@ pub mod test_util {
         }
     }
 
-    fn setup_test_dir() {
+    /// 准备测试环境，切换到测试目录
+    fn setup_test_env() {
         color_backtrace::install(); // colorize backtrace
+
         let mut path = find_cargo_dir();
         path.push(TEST_DIR);
         if !path.exists() {
             fs::create_dir(&path).unwrap();
         }
-        std::env::set_current_dir(&path).unwrap();
+        std::env::set_current_dir(&path).unwrap(); // 将执行目录切换到测试目录
+    }
+
+    pub fn init_mit() {
+        let _ = crate::commands::init();
+        Index::reload(); // 重置index, 以防止其他测试修改了index单例
     }
 
     /// with 初始化的干净的mit
     pub fn setup_test_with_clean_mit() {
         setup_test_without_mit();
-        let _ = crate::commands::init::init();
+        init_mit();
     }
 
     pub fn setup_test_without_mit() {
         // 将执行目录切换到测试目录，并清除测试目录下的.mit目录
-        setup_test_dir();
-        let mut path = std::env::current_dir().unwrap();
+        setup_test_env();
+        let mut path = cur_dir();
         path.push(ROOT_DIR);
         if path.exists() {
             fs::remove_dir_all(&path).unwrap();
@@ -101,13 +106,13 @@ pub mod test_util {
         }
     }
 
-    pub fn ensure_no_file(path: &Path) {
-        // 以测试目录为根目录，删除文件
-        if path.exists() {
-            fs::remove_file(get_working_dir().unwrap().join(path)).unwrap();
-        }
+pub fn ensure_no_file(path: &Path) {
+    // 以测试目录为根目录，删除文件
+    if path.exists() {
+        fs::remove_file(get_working_dir().unwrap().join(path)).unwrap();
     }
 }
+}
 /* tools for mit */
 pub fn calc_hash(data: &String) -> String {
     let mut hasher = Sha1::new();
@@ -529,9 +534,9 @@ pub fn is_typeof_commit(hash: Hash) -> bool {
 #[cfg(test)]
 mod tests {
     use crate::models::{blob::Blob, index::Index};
-
     use super::*;
     use super::test_util::*;
+
     #[test]
     fn test_get_storage_path() {
         let path = get_storage_path();