In order to solve the problem that the hydraulic cylinder grab fails to grasp and release due to the positioning error of the cylinder grab during the delivery test,which leads to the damage of the test bench and affects the working efficiency,in order to realize the rapid and accurate grasp of the cylinder,the fuzzy PID control algorithm was adopted to realize the step positioning control of the cylinder gripper of the multi-position cylinder test bench.The test object of the multi-position cylinder test bench was a two-phase hybrid stepping motor.Through the simulation analysis for fixed parameter PID,the optimal PID parameters of the system were Kp=22, Ki=0.26, Kd=1.40.Under the parameters,through the comparative analysis of fuzzy PID control and fixed parameter PID control,it was concluded that the time and response speed required for the fuzzy PID control to achieve the system steady state were better than the fixed parameter PID control system.After the disturbance was added,the control effects of fuzzy PID control and fixed parameter PID control were compared and analyzed.In the workshop disturbance environment,the stepping motor control system responds quickly and controls stably,and the fuzzy PID control effect is obviously better than the fixed parameter PID control.Finally,it is proved that the fuzzy PID optimization control algorithm meets the requirements of the positioning accuracy of the cylinder gripper through the offline workshop test bench.