A direct drive volume control pressure model based on AMESim and Simulink co-simulation was established to solve the problems of motor delay, system dead zone nonlinearity, system overshoot and pressure fluctuation in differential cylinder conversion.The fuzzy PID controller was designed and compared with the traditional PID controller. Through simulation, it is verified that the fuzzy PID controller has good effect in solving problems such as motor delay, system dead zone, system overshooting and pressure fluctuation.