Abstract: The design of bi-directional DC-DC converter(BDC)consists of 4 major components, such as PWM control, driving, power conversion, and measurement and control.TL494 PWM control component use TL494 as the control core, closed-loop regulates circuit duty cycle; PWM drive component constitutes of IR2111, drive switch synchronous rectification circuit; power conversion component with synchronous rectification circuit is a power conversion topology to achieve bi-directional DC-DC high-efficiency power conversion; control circuit MSP430 MCU as controller, combined with current, voltage sampling circuit, a control circuit output parameters and displayed.Systems with overcurrent, overvoltage protection, and can achieve high-precision programmable MSP430 microcontroller.Test results show that: the synchronous rectifier circuit can better complete bi-directional DC-DC power conversion, bi-directional power conversion efficiency reached 95% or more, and also has strong ability of anti-disturbance.