The reversing collision avoidance system is a kind of auxiliary car parking device.The system consists of ultrasonic transceiver circuit, signal amplification circuit,voice prompt circuit,digital display mode,and alarm and temperature compensation circuit.The hardware circuit and software program of the system were studied in this paper, and the hardware system design and software work flow were designed.We selected STC11F02E singlechip microcomputer as the control chip of the hardware,API8108A voice chip was used to design the voice prompt system, DS18B20 temperature sensor was used to measure the temperature and realize temperature compensation of the ranging, two pieces of 74LS164 seriesparallel conversion chip were used to realize realtime display of 5piece digital tubes.The ranging and display programs were mainly introduced.The system was tested to verify the accuracy and reliability. The results showed that the system had a certain practical application.