The hybrid vehicle is a new type of green and energy efficient vehicle. Hydraulic accumulator and variable pump/motor make up the break energy regeneration utilization system, which is the core of hydraulic auxiliary driving unit. The hybrid drive system is composed of hydraulic auxiliary driving unit and the original vehicle drive system. As it relates to the recovery of the braking energy and the situation of two kinds of power-driven vehicle, it brings complexity to the hybrid distribution strategy, and an efficient energy control system is necessary. Based on CAN bus technology, using the CAN2.0B communication protocol for the system design, the core hardware system is composed of PC/104 computer and CAN communication card, the key nodes of hydraulic auxiliary drive unit use DSP chip TMS320LF2407. Experiments show that the system has a high communication reliability and high accuracy of dynamic coupling, the safety of vehicles and the best energy matching.