Long-distance ultrasonic radars are installed on actual vehicles, with 2 at the front and 4 at the rear. When the vehicle passes through an empty parking space, the long-distance ultrasonic radar can sense the obstacles around it and identify the parking space. The results show that the ultrasonic radar is controlled through LIN bus serial communication network and through digital signal substitute for analog signal, and the lateral and longitudinal parking spaces calculated through fitting curve enjoy advantages of being accurate, simple, practical, effective, and low-cost. Thus, it can create conditions for application of intelligent parking technology in medium and low-end cars, and provide more theoretical basis for improvement of practical operations.