Global Positioning System（GPS）is able to identify real-time information of moving objects quickly and efficiently, such as longitude, latitude, altitude, time and so on. So it has to give the positioning and navigation of objects. This research uses GPS9540 receiver module to receive satellite signals. The time information and location information of this kind of GPS receiver module is GPRMC statement of NMEA-0183 standard format. We use AT89C51 Single Chip Microcomputer (SCM) of ATMEL Corporation as the core controller, and use the serial port of SCM to receive the time information and location information of GPS receiver module. We adjust the time difference information of the GPS receiver module, and finally display acquired location and time information through the liquid crystal display module (LCD). Actual operating results show that the system can decode GPS location information and time information correctly, and positioning information and time information is displayed on the LCD correctly. The system has good reliability and practicality, and it can be used for object location and navigation. This research first introduces the applications and theory of GPS as well as the extraction methods of GPS module output data. Then we introduce the system hardware block diagram and schematic, as well as system software flow chart and software programming, thus we achieve the key technology research of the GPS positioning system.