diff --git a/library/think/log/driver/File.php b/library/think/log/driver/File.php
index a540aac0..bbc9b76e 100644
--- a/library/think/log/driver/File.php
+++ b/library/think/log/driver/File.php
@@ -54,12 +54,12 @@ class File
         } else {
             $current_uri = "cmd:" . implode(' ', $_SERVER['argv']);
         }
-        $runtime    = number_format(microtime(true), 8, '.', '') - THINK_START_TIME;
-        $reqs       = number_format(1 / $runtime, 2);
-        $time_str   = " [运行时间：{$runtime}s] [吞吐率：{$reqs}req/s]";
+        $runtime    = (number_format(microtime(true), 8, '.', '') - THINK_START_TIME) ?: 0.00000001;
+        $reqs       = number_format(1 / number_format($runtime, 8), 2);
+        $time_str   = ' [运行时间：' . number_format($runtime, 6) . 's][吞吐率：' . $reqs . 'req/s]';
         $memory_use = number_format((memory_get_usage() - THINK_START_MEM) / 1024, 2);
-        $memory_str = " [内存消耗：{$memory_use}kb]";
-        $file_load  = " [文件加载：" . count(get_included_files()) . "]";
+        $memory_str = ' [内存消耗：' . $memory_use . 'kb]';
+        $file_load  = ' [文件加载：' . count(get_included_files()) . ']';
 
         $info = '[ log ] ' . $current_uri . $time_str . $memory_str . $file_load . "\r\n";
         foreach ($log as $type => $val) {