thank you ~ ， your advice worked ！！！ My problem is git command can’t execute, log likes Cannot run program “git” …… then i add ‘-Djdk.lang.Process.launchMechanism=vfork’ this in jenkins.service file . and then i restart the jenkins program. it is useful .finally i sercher why it worked: vfork is a mode that can reduce memory usage when jenkins try to execute git command.