According to the code correlation features of GPS, this paper proposes the interference detection method for the repeater deception jamming satellite signal based on Fast Fourier Transform Algorithm, and it could output the correlation values of multiple code phases only one time. The interference detection method uses the features of forward single delay to true single, and the forward spoofing single is the delayed correlation peak single over detection threshold. The simulation results show that the interference detection method could identify effectively the forward spoofing single that forward delay is not less than 1.5chips.