For primary user emulation (PUE) attack signal difficulty in emulating space-time cyclostationarity of primary user (PU) signal, a detection method based on cyclic space-time filtering is produced. First, cyclic space-time filter is designed by using prior information of PU signal characteristic in space-time, and then the filtered signal is detected by theshold power detection. Then, the local detection results are sent to fustion center (FC) to make a global decision. The local results are devided into different groups according to cyclic frequency. The global decision is obtained based on double fusion rule in and between groups. Last, the multi-user cooperative detection in diversity is efficient in reducing error detection and computation complexity. The simulation results show that the proposed method is effectively working in low signal to interference and noise ratio and has high performance in measurements.