diff --git a/src/cluster.rs b/src/cluster.rs
index fc5117d..9c3a0c0 100644
--- a/src/cluster.rs
+++ b/src/cluster.rs
@@ -123,6 +123,7 @@ mod tests {
             test_conf.cluster_id,
             test_conf.cluster_secret,
             None,
+            None,
         )
     }
 
diff --git a/src/config.rs b/src/config.rs
index 82bfaff..0da7bb1 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,15 +1,14 @@
 use {
     crate::fatal,
     log::{error, info, warn},
-    std::{env, fs},
-    serde::{Serialize, Deserialize}
+    serde::{Deserialize, Serialize},
+    std::{env, fs, path::PathBuf},
 };
 
 const CONFIG_PATH: &str = "config.toml";
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct Config {
-    /// http or https
     /// CENTER_URL
     pub center_url: String,
     /// CLUSTER_IP
@@ -22,6 +21,8 @@ pub struct Config {
     pub cluster_secret: String,
     /// NO_DEMAON
     pub no_demaon: bool,
+    /// cache dir
+    pub cache_dir: PathBuf,
 }
 
 impl Config {
@@ -32,7 +33,16 @@ impl Config {
         cluster_id: String,
         cluster_secret: String,
         no_demaon: Option<bool>,
+        cache_dir: Option<PathBuf>,
     ) -> Self {
+        // cache dir 默认: cwd + 'cache'
+        let cache_dir = if let Some(cache_dir) = cache_dir {
+            cache_dir
+        } else {
+            env::current_dir()
+                .unwrap_or(PathBuf::from("."))
+                .join("cache")
+        };
         Self {
             center_url: center_url.unwrap_or("https://openbmclapi.bangbang93.com".to_string()),
             host_ip: host_ip.unwrap_or("0.0.0.0".to_string()),
@@ -40,6 +50,7 @@ impl Config {
             cluster_id,
             cluster_secret,
             no_demaon: no_demaon.unwrap_or(false),
+            cache_dir,
         }
     }
 
@@ -49,12 +60,13 @@ impl Config {
         let host_ip = env::var("CLUSTER_IP").ok();
         let host_port = env::var("CLUSTER_PORT").unwrap().parse::<u32>().ok();
         let no_demaon = env::var("NO_DAEMON").unwrap().parse::<bool>().ok();
+        let cache_dir = env::var("CACHE_DIR").ok().map(|x| PathBuf::from(x));
 
         // Load from env
-        let cluster_id = env::var("CLUSTER_ID").unwrap_or_else(|err| {
+        let cluster_id = env::var("CLUSTER_ID").unwrap_or_else(|_| {
             fatal!("CLUSTER_ID must be set");
         });
-        let cluster_secret = env::var("CLUSTER_SECRET").unwrap_or_else(|err| {
+        let cluster_secret = env::var("CLUSTER_SECRET").unwrap_or_else(|_| {
             fatal!("CLUSTER_SECRET must be set");
         });
 
@@ -81,6 +93,7 @@ impl Config {
             cluster_id,
             cluster_secret,
             no_demaon,
+            cache_dir,
         );
 
         // Save config
diff --git a/src/serve.rs b/src/serve.rs
index 2f7a92b..8ccf23b 100644
--- a/src/serve.rs
+++ b/src/serve.rs
@@ -1,7 +1,9 @@
+use crate::{config::Config, utils::hash_to_filename};
+
 use std::collections::HashMap;
 
 use axum::{
-    extract::{Path, Query},
+    extract::{Path, Query, State},
     http::header::HeaderMap,
     http::StatusCode,
     response::{IntoResponse, Response},
@@ -10,7 +12,7 @@ use axum::{
 pub enum MeasureRes {
     Forbidden,
     BadResquest,
-    Data(Vec<u8>)
+    Data(Vec<u8>),
 }
 
 impl IntoResponse for MeasureRes {
@@ -18,7 +20,7 @@ impl IntoResponse for MeasureRes {
         match self {
             Self::Forbidden => (StatusCode::FORBIDDEN).into_response(),
             Self::BadResquest => (StatusCode::BAD_REQUEST).into_response(),
-            Self::Data(data) => (StatusCode::OK, data).into_response()
+            Self::Data(data) => (StatusCode::OK, data).into_response(),
         }
     }
 }
@@ -45,7 +47,6 @@ impl IntoResponse for MeasureRes {
 ///
 /// export default MeasureRoute
 /// ```
-/// 
 pub async fn measure(header: HeaderMap, Path(size): Path<u32>) -> MeasureRes {
     match header.get("x-openbmclapi-secret") {
         Some(secret) => {
@@ -60,12 +61,20 @@ pub async fn measure(header: HeaderMap, Path(size): Path<u32>) -> MeasureRes {
             data.fill(114_u8);
             return MeasureRes::Data(data);
         }
-        None => MeasureRes::Forbidden
+        None => MeasureRes::Forbidden,
     }
 }
 
 /// 返回文件的请求函数
 /// app.get('/download/:hash(\\w+)', async (req: Request, res: Response, next: NextFunction) => {
-pub async fn res_donwload(header: HeaderMap, Query(param): Query<HashMap<String, String>>, Path(hash): Path<String>) -> impl IntoResponse {
+pub async fn res_donwload(
+    State(config): State<Config>,
+    header: HeaderMap,
+    Query(param): Query<HashMap<String, String>>,
+    Path(hash): Path<String>,
+) -> impl IntoResponse {
+    let hash = hash.to_lowercase();
+    let file_path = config.cache_dir.join(hash_to_filename(&hash));
+    
     todo!();
 }