High-precision positioning is one of the core technologies to realize autonomous driving. It works as follows: GNSS signals are received from BDS, GPS, GLONASS and GALILEO through high-precision positioning antenna; and simultaneously, RTK differential data is received from ground based augmentation system through 4G and 5G antennas. In the SOC of GNSS positioning antenna, various errors on the data chain are eliminated through RTK algorithm, then centimeter-level and even millimeter-level positioning accuracy can be achieved. The whole process provides stable and reliable absolute positioning information for the high-precision fusion positioning system