The weaknesses of GPS (Global Positioning System) is vulnerable to be jammed, so the study of jamming and anti-jamming of GPS has drawn more and more attention. In this paper, it analyzes the performance of GPS jamming and the anti-jamming of GPS receiver about blanket jamming. In addition, it establishes the simulation model based on MATLAB and gives the analysis of the performance of the anti-jamming about GPS receiver by adding the C/A code jamming and single-frequency jamming. Finally, based on the simulation, it analyzes the effect on GPS receiver by adding C/A code jamming and single-frequency jamming; and it achieves the analysis of the anti-jamming of GPS after the bit error decision, which proves that GPS have some ability of anti-noise and anti-jamming.