Abstract: Objective To test the accuracy, the reliability and the stability of flow-controlling method of a new percutaneous left ventricular assist device. Methods With the AMEsim to set up a simulation model, analysis the variations of motor speed, flow and pressure by adjusting the size of valve. and we test the improved-theoretical model with outside experiment. Results In the simulation experiment, with the variations of pressure from A, the system can regulate the motor speed to maintain the pump outlet pressure 1.1×10⁵ Pa~1.2×10⁵ Pa and control the flow. With the B valve size changes, the flow-controlling by the system identify and change the motor speed, to maintain the pump inlet pressure from -0.25×10⁵ Pa to -0.10×10⁵ Pa. In outside experiment, with the variations of the size of valve A and valve B, the pump can change the voltage by self-regulation, maintain the entrance and exit of pressure is relatively stable and control the flow. Conclusions It is a fast-responding and better robust way, by adding the pressure sensor to adjust the speed of motor, to control the flow accurately.