Abstract: This paper presented a new FFT-based parallel acquisition algorithm, which modified the traditional FFT-based acquisition, cut down the computation and shortened the acquisition time needed for long time integration in weak GPS acquisition through block addition and circular shift of FFT, then detailed the theory model of algorithm and simulated the algorithms with real GPS signal on Matlab platform in the later part of this paper.The experiment results showed that signals below-150dBm could be acquired successfully with integration time less than 150ms.