First of all you seem to have developed the nasty habit of selectively responding to replies in your own threads. I suggest you revisit your old threads and either post a follow up or post the solution and mark these threads "solved".
Originally Posted by luofeiyu
root@pengsir:~# service nginx start
Failed to start nginx.service: Unit nginx.service failed to load: No such file or directory.
...next to that I think you have posted partial information here which also leads me to believe (also from the questions you posted) that you should not be installing things but would benefit from first reading your Linux distributions basic user and admin documentation. Services may require configuration and pre-flight testing prior to launching them. Just ignoring the configuration part, clues on stdout / stderr or log file entries is no guarantee for success.