手动录入端口

新建一个bat文件，内容如下：

@ECHO OFF
set /p portid=Enter the Port to be killed: 
echo %portid%                                                                              
FOR /F "tokens=5" %%T IN ('netstat -a -n -o ^| findstr %portid% ') DO (
SET /A ProcessId=%%T) &GOTO SkipLine                                                   
:SkipLine                                                                              
echo ProcessId to kill = %ProcessId%
taskkill /f /pid %ProcessId%
PAUSE

双击运行后，输入端口号即可杀掉对应的进程。

固定端口

set portid=12306
echo %portid%                                                                              
FOR /F "tokens=5" %%T IN ('netstat -a -n -o ^| findstr %portid% ') DO (
SET /A ProcessId=%%T) &GOTO SkipLine                                                   
:SkipLine                                                                              
echo ProcessId to kill = %ProcessId%
taskkill /f /pid %ProcessId%

参考

https://stackoverflow.com/questions/6204003/kill-a-process-by-looking-up-the-port-being-used-by-it-from-a-bat