This paper uses AVR16 SCM, programming to achieve the software of PWM (pulse width modulation) control of intelligent H bridge chip LMD18200 driver of high speed DC motor, makes special speed tablet, obtains speed signal of high speed for photocoupler PC817, through the A/D conversion and processing circuit, and realizes the LED LCD digital display speed scheme. The driver for the pediatric ventricular assist device has been used at the laboratory trial, has high performance and wide application prospect.