Based on analyzing the structure and motion characteristics of belt wrapper,its hydraulic circuit was designed,and the hydraulic circuit was simulated using simulation software.In the commissioning process,according to the failure phenomenon,the cause of the problem was found by experiment method,and the problem was successfully resolved.Through the solving process of the issue,it is known that when designing hydraulic principles,not only reasonable hydraulic circuit and valves should be chosen,but also internal leaks of hydraulic cylinder should be taken into account.