Aiming at problem that traditional ultrasonic wave reversing radar in large cars such as large trucks can only detect the horizontal direction

but cannot detect obstacles on the ground and in the air

which is prone to hit the aerial obstacles

a multi-directional backup-aided system based on ultrasonic wave ranging is designed

and the corresponding voice prompts are issued according to the types of obstacles. The experimental results show that the system can not only detect obstacle in horizontal direction and in the air

but also can detect ground gully and bulge. The system can realize accurate ranging in the range of 30～ 400 cm

the maximum error is less than 1. 6 %

it has certain research and application value.