Ultrasonic ranging (UR) technology has being used widely in many industries around the world. This paper aims to design and manufacture an ultrasonic distance measuring system with lower price and higher accuracy. Based on the deep study of principle of ultrasonic ranging, we designed the general plan and detailed electrical circuits for the ultrasonic distance measuring system based on single chip microprocessor of AT89S52, including the transmitter module of ultrasonic wave, receiving module of ultrasonic wave, display module etc. Then, we compiled the relative driven programs for all modules. After that, we debugged the combined system of hardware and software system. At last, the experimental results show that the cost is about 300RMB for 3 prototypes, measuring rang is 0.16 similar to 1.5m with the accuracy of 0.001mm, which means the ranging system meets the design requirements of lower price and higher accuracy.