Abstract: In order to improve the control characteristics of load sensing pump control system, a dynamic mathematical model and a dynamic simulation model of load sensing pump control system were established, and the correctness of the models were verified by bench test. Based on the dynamic model, the influence of the key matching parameters of the displacement control mechanism on the flow control accuracy of load sensing pump control system and the energy consumption characteristics of the displacement control mechanism was emphatically analyzed. The results show that proper radial fit clearance of load sensing valve and pressure shut-off valve and proper negative cover amount of load sensing valve port are not only conducive to improve the flow control accuracy of load sensing pump control system, but also constrain the energy consumption of displacement control mechanism at a low level. Excessive clearance and excessive negative cover amount will not only greatly increase the throttling loss of displacement control mechanism, but also greatly reduce the flow control accuracy of load sensing pump control system.