In order to solve the problem that some phase shift keying signals in some bandwidth cannot be detected in communication to submarine, a chaotic detection method of the short code length PSK signal is proposed based on the principle of detecting the PSK signal by the chaotic oscillator. The a priori phase information is extracted by using the correlation coefficient between the PSK signals, and the inherent carrier information is used to generate the sequence to be tested. A new discriminant basis is constructed to perform phase discrimination. Taking 8PSK signals for example to simulate, the results show that this method can realize detection and keep better detection ability than traditional coherent detection and incoherent detection, and the amount of traditional chaotic detection computation has been cut down.