The invention discloses a millimeter wave radar system of an auxiliary driving system of a motorcycle and an electric vehicle. The millimeter wave radar system comprises a vehicle body, a forward millimeter wave radar, a backward millimeter wave radar, radar circuit boards, radar antennas, processors, a power interface, a millimeter wave front end circuit, a millimeter wave back end circuit, an intermediate frequency amplification module, a conditioning module, an analog-digital signal conversion module, a baseband signal processing module and a monitoring camera, wherein the forward millimeter wave radar is arranged at one end of the vehicle body, and the other end of the vehicle body is provided with the backward millimeter wave radar, and the radar circuit boards are arranged inside theforward millimeter wave radar and the backward millimeter wave radar, the radar antennas are arranged on the surfaces of the radar circuit boards, and the processors are arranged on the back of the radar circuit boards. The system can be used for combing the observation results of the forward millimeter wave radar and the backward millimeter wave radar and the identification result of the monitoring camera, the observation precision is further improved, and the information amount of the target position information is more abundant.