With the development of the GPS spoofing signal generating technology, the spoofing signal can be similar to the authentic signal in such attributes as arrival angle and Doppler frequency, making it difficult to detect the spoofing signal by only employing one spoofing interference detection method. While if directly combining several methods, the detection performance will be decreased when one detector is degraded. Thus, considering that under different deception jamming scenarios, the detection performance of detectors has real-time changes and the priori information is missing, a detection fusion method is proposed in this paper to detect spoofing signals by evaluating real-time performance of detectors. By establishing the evaluation criteria for performance error, the real-time performance comparison between the proposed method and the single detector method was conducted. With this method, the degraded detector will be rejected if the performance falls down below the threshold, which can ensure that when a detector fails, it will not affect the overall performance of the fusion. This method can be applied to the fusion of any number and any kind of deception detection methods. Based on the detection methods of phase difference and carrier Doppler variance, an engineering implementation method is presented in this paper. Finally, simulation results showed that the spoofing detection fusion algorithm for real-time performance evaluation had better deception performance and wider adaptability than one detector and traditional detection fusion algorithms.