diff --git a/Cargo.toml b/Cargo.toml
index f8c7055..12d6d9b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,7 +6,7 @@ members = [
 
 [package]
 name = "fast_log"
-version = "1.7.1"
+version = "1.7.2"
 description = "Rust async log High-performance asynchronous logging"
 readme = "Readme.md"
 authors = ["ce <zhuxiujia@qq.com>"]
diff --git a/src/plugin/console.rs b/src/plugin/console.rs
index ceb9060..64c2a9c 100644
--- a/src/plugin/console.rs
+++ b/src/plugin/console.rs
@@ -8,7 +8,14 @@ impl LogAppender for ConsoleAppender {
         if records.len() == 0 {
             return;
         }
-        let mut buffer = String::with_capacity(records.len());
+        let mut cap = 0;
+        if records.len() != 0 {
+            cap = 0;
+            for x in records {
+                cap += x.formated.len();
+            }
+        }
+        let mut buffer = String::with_capacity(cap);
         for x in records {
             buffer.push_str(&x.formated);
         }
diff --git a/src/plugin/file.rs b/src/plugin/file.rs
index af82283..9f48c78 100644
--- a/src/plugin/file.rs
+++ b/src/plugin/file.rs
@@ -30,7 +30,14 @@ impl FileAppender {
 impl LogAppender for FileAppender {
     fn do_logs(&mut self, records: &[FastLogRecord]) {
         let mut log_file = self.file.borrow_mut();
-        let mut buf = String::new();
+        let mut cap = 0;
+        if records.len() != 0 {
+            cap = 0;
+            for x in records {
+                cap += x.formated.len();
+            }
+        }
+        let mut buf = String::with_capacity(cap);
         for x in records {
             buf.push_str(&x.formated);
             match &x.command {
diff --git a/src/plugin/file_split.rs b/src/plugin/file_split.rs
index 360595d..1c890f9 100644
--- a/src/plugin/file_split.rs
+++ b/src/plugin/file_split.rs
@@ -491,7 +491,14 @@ impl Keep for KeepType {
 impl LogAppender for FileSplitAppender {
     fn do_logs(&mut self, records: &[FastLogRecord]) {
         //if temp_bytes is full,must send pack
-        let mut temp = String::with_capacity(records.len() * 10);
+        let mut cap = 0;
+        if records.len() != 0 {
+            cap = 0;
+            for x in records {
+                cap += x.formated.len();
+            }
+        }
+        let mut temp = String::with_capacity(cap);
         for x in records {
             match x.command {
                 Command::CommandRecord => {