Focus on the problem of small opening jitter due to condition of high temperature and heavy load in a certain type of car crane, The simulation model of the system is established by using AMESim software, By simulating the cause of the jitter and the solution are found and verified in the test, The test results show that the bypass circuit of 1.5mm damping can significantly improve the fretting of the winch system, and the problem of decentralized jitter is solved.