According to the fly's eye bionics principle, a low speed collision and warning system for large mining trucks based on ultrasonic spread spectrum ranging system with pseudo random code and CAN bus has been proposed. The system used DSP as core controller, four groups of 12 ultrasonic sensors distributed around the truck as compound eyes, through 3 ultrasonic sensors data association of each group to realize no blind area ranging and all round obstacle avoidance. The structure, principle, hardware and software design are described in detail. The experiment results show that the measuring distance, precision, accuracy and immunity are all at high levels and can satisfy the low speed collision and warning requirements of large mining trucks.