For the fact that the spoofer has no way to simulate the space distribution characteristic of the authentic GNSS（global navigation satellite system） signals, a detection technique based on carry phase difference was proposed. All errors of the detection were analyzed, and the multiple hypotheses testing the spoofing detection were built. Through theoretical analysis and simulation tests, the proposed spoofing detection method is verified. Results show that the longer the baseline of the array is, the smaller angle of incidence is, which leads to a better spoofing detection performance of the proposed method.