diff --git a/config.json b/config.json
index bfc5193..90430f3 100644
--- a/config.json
+++ b/config.json
@@ -1,14 +1,16 @@
 {
-  "server_ip": "127.0.0.1",
-  "server_port": "25565",
-  "proxy_url": "",
-  "username_prefix": "test",
-  "worker_threads": 100,
-  "use_thread_pool": false,
+  "server_ip": "m.earthvillage.top",
+  "server_port": "33009",
+  "username_prefix": "",
   "count": 300,
-  "reco_words": ["验证程序已启用","AntiAttack"],
-  "login_commands": ["reg helloa helloa"],
-  "spam_file": "test.txt",
-  "spam_delay_ms": 1000,
-  "random_prefix": true
+  "proxy_url": "http://uu-proxy.com/api/get_proxies?id=RZ7GS5ZYTA&size=1&schemes=socks5&support_https=false&format=json",
+  "reco_words": [
+    "AntiAttack"
+  ],
+  "login_commands": [],
+  "spam_file": "",
+  "spam_delay_ms": 0,
+  "random_prefix": false,
+  "worker_threads": 100,
+  "use_thread_pool": true
 }
\ No newline at end of file
diff --git a/src/bot_socks5.rs b/src/bot_socks5.rs
index aba4ccf..b698a66 100644
--- a/src/bot_socks5.rs
+++ b/src/bot_socks5.rs
@@ -293,7 +293,7 @@ impl<T: StreamType> Bot<T> {
                 if !self.config.spam_file().is_empty() && iter % self.config.spam_delay_ms() == 0{
                     let mut msg = String::new();
                     if self.config.random_prefix(){
-                        msg += &utils::generate_string();
+                        msg += &utils::generate_string(2,10);
                     }
                     { // TODO 优化这里
                         let var = self.var.clone();
diff --git a/src/configuration.rs b/src/configuration.rs
index f2dc23a..39890e2 100644
--- a/src/configuration.rs
+++ b/src/configuration.rs
@@ -1,4 +1,4 @@
-use std::fs::File;
+use std::{fs::File, io::BufWriter};
 use serde::{Deserialize, Serialize};
 use std::io::BufReader;
 
@@ -41,6 +41,11 @@ impl Configuration {
             }
             Err(error) => {
                 eprintln!("[MAIN/CONF] Unable to read config file, will use default values: {}", error);
+                let file = File::create_new(filename).unwrap();
+                let writer = BufWriter::new(file);
+                let mut serializer = serde_json::Serializer::pretty(writer);
+                Self::default().serialize(&mut serializer).unwrap();
+                eprintln!("[Main/CONF] A configure file with default values is created.");
                 Self::default()
             }
         }
@@ -48,7 +53,7 @@ impl Configuration {
 
     fn default() -> Self {
         Configuration {
-            server_ip: "49.70.3.146".to_string(),
+            server_ip: "m.earthvillage.top".to_string(),
             server_port: "33009".to_string(),
             username_prefix: "".to_string(),
             count: 300,
@@ -59,7 +64,7 @@ impl Configuration {
             spam_delay_ms: 0,
             random_prefix: false,
             worker_threads: 100,
-            use_thread_pool: true
+            use_thread_pool: true,
         }
     }
 
diff --git a/src/main.rs b/src/main.rs
index e33c604..ee1bb4a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -35,6 +35,10 @@ async fn main() {
     let configuration = Configuration::new("config.json");
     let configuration_rc = Arc::new(configuration);
     let mut spam_file = None;
+    if configuration_rc.username_prefix().len() > 14 {
+        eprintln!("[CONFIG] Error: Username prefix should not longer than 14");
+        return;
+    }
     if !configuration_rc.clone().spam_file().is_empty() {
         spam_file = Some(tokio::fs::File::open(configuration_rc.clone().spam_file()).await.unwrap());
     }
@@ -145,22 +149,9 @@ async fn attack_thread(lock: Arc<Mutex<()>>, config: Arc<Configuration>, variabl
                 // 插入生成update_worker线程的代码
                 let mut bot_clone = bot.clone();
                 let (tx, rx) = tokio::sync::mpsc::unbounded_channel::<u8>();
-                if config.use_thread_pool {
-                    tokio::spawn(async move {
-                        bot_clone.update_worker(rx).await;
-                    });
-                }else {
-                    thread::spawn(|| {
-                        tokio::runtime::Builder::new_current_thread()
-                            .enable_all()
-                            .thread_stack_size(8 * 1024 * 1024)
-                            .build()
-                            .unwrap()
-                            .block_on(async move {
-                                bot_clone.update_worker(rx).await
-                            });
-                    });
-                }
+                tokio::spawn(async move {
+                    bot_clone.update_worker(rx).await;
+                });
                 match bot.run(tx).await {
                     Ok(_) => {
                         if bot.should_restart() {
diff --git a/src/utils.rs b/src/utils.rs
index 9661cd9..0037cd0 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -46,15 +46,17 @@ pub fn parse_json_component(json: &str) -> String {
 
 // 生成一个随机的用户名
 // author: 通义
-pub fn generate_string() -> String {
+pub fn generate_string(len_min: i64, len_max: i64) -> String {
     let mut rng = rand::thread_rng();
-    let len = rng.gen_range(5..=10);
+    let len = rng.gen_range(len_min..=len_max);
     rng.sample_iter(&Alphanumeric)
-        .take(len)
+        .take(len as usize)
         .map(char::from)
         .collect()
 }
 
 pub fn generate_username(config: &Arc<Configuration>) -> String {
-   config.username_prefix().to_string() + generate_string().to_string().as_str()
+   config.username_prefix().to_string() + generate_string(
+    2,16-config.username_prefix().len() as i64
+   ).to_string().as_str()
 }
\ No newline at end of file