感谢@zhangqiang 帮助解决，错误原因是输出验证码的时候前面带了3个空格导致的。自我分析可能是用记事本修改代码文件造成的。   --------------     基本信息：阿里云Linux服务器，WC版本为3.0.2   1、cache和TMP的权限已设置为777，并且captcha清空之后测试，可以自动生成验证码图片文件 2、验证码右键打开显示为乱码 3、已装有GD库，具体信息如下   4、php-fpm.log近期日志   [28-Jan-2015 11:44:43] WARNING: [pool www] child 4503 exited on signal 6 (SIGABRT) after 59.554494 seconds from start [28-Jan-2015 11:44:43] NOTICE: [pool www] child 4545 started [28-Jan-2015 11:44:46] WARNING: [pool www] child 4504 exited on signal 6 (SIGABRT) after 59.560354 seconds from start [28-Jan-2015 11:44:46] NOTICE: [pool www] child 4546 started [28-Jan-2015 11:44:48] WARNING: [pool www] child 4505 exited on signal 6 (SIGABRT) after 60.321597 seconds from start [28-Jan-2015 11:44:48] NOTICE: [pool www] child 4547 started [28-Jan-2015 11:44:54] WARNING: [pool www] child 4507 exited on signal 6 (SIGABRT) after 60.605742 seconds from start [28-Jan-2015 11:44:54] NOTICE: [pool www] child 4549 started [28-Jan-2015 11:44:56] WARNING: [pool www] child 4508 exited on signal 6 (SIGABRT) after 61.612078 seconds from start [28-Jan-2015 11:44:56] NOTICE: [pool www] child 4550 started [28-Jan-2015 11:44:57] WARNING: [pool www] child 4510 exited on signal 6 (SIGABRT) after 60.619858 seconds from start [28-Jan-2015 11:44:57] NOTICE: [pool www] child 4552 started [28-Jan-2015 11:44:59] WARNING: [pool www] child 4511 exited on signal 6 (SIGABRT) after 59.662843 seconds from start [28-Jan-2015 11:44:59] NOTICE: [pool www] child 4553 started [28-Jan-2015 11:45:00] WARNING: [pool www] child 4516 exited on signal 6 (SIGABRT) after 58.685026 seconds from start [28-Jan-2015 11:45:00] NOTICE: [pool www] child 4554 started [28-Jan-2015 11:45:04] WARNING: [pool www] child 4531 exited on signal 6 (SIGABRT) after 58.753835 seconds from start [28-Jan-2015 11:45:04] NOTICE: [pool www] child 4574 started [28-Jan-2015 11:45:09] WARNING: [pool www] child 4532 exited on signal 6 (SIGABRT) after 59.792261 seconds from start [28-Jan-2015 11:45:09] NOTICE: [pool www] child 4575 started [28-Jan-2015 11:45:10] WARNING: [pool www] child 4533 exited on signal 6 (SIGABRT) after 58.796966 seconds from start [28-Jan-2015 11:45:10] NOTICE: [pool www] child 4576 started [28-Jan-2015 11:45:11] WARNING: [pool www] child 4534 exited on signal 6 (SIGABRT) after 58.805936 seconds from start [28-Jan-2015 11:45:11] NOTICE: [pool www] child 4577 started