Abstract: Global Navigation Satellite System (GNSS) can provide users with positioning, navigation and timing services, and is widely used in national defense security and national economic construction. Real time precise point positioning (PPP) is a high precise satellite navigation positioning method, this paper discusses the current problems of the algorithm that long reinitialization time caused by signal interruption , and proposes a cycle slip repair algorithm based on the differential pseudorange and carrier phase observations. It designs a real-time precise point positioning algorithm and introduces its implementation process. The success rate of the cycle slip repair experiment using the data of the IGS observatory is more than 99%, and shorten the reconvergence time. The cart experiment was carrier out on the roof of the building, and the real-time precise point positioning accuracy was better than 1 cm in the horizontal direction, and the accuracy was 2~3 cm in the vertical direction.