Fast movement of space satellite, difference of clocks and high dynamics of the application platform of GPS receivers are important factors to influence signal synchronization. In order to handle the challenges of these factors on system synchronization and achieve rapid and correct demodulation of navigation data, a synchronous algorithm of GPS software receivers was put forward on the base of profound study of circumference correlation acquisition algorithms, non-correlated lead-lag code tracking loops and operational principles of Costas carrier tracking circle, whose validity and rationality were tested by simulation for providing realistic grounds for our country to develop application platforms of GPS receivers.