Abstract: Aiming at the different signal characteristics of the anti-radiation missile(ARM) and its aircraft,an improved method is proposed to restrain the aircraft signal.Firstly the aircraft signal’s Doppler frequency is estimated,then the phase of the delay signal is compensated with the estimation,lastly the aircraft signal is restrained when the delay signal is subtracted from the original signal.After restraining the aircraft signal,based on the assumption of autoregressive(AR) process correlated clutter,the paper presents the Rao decision rule of the ARM detection.The Rao test algorithm is practicable and almost has the same performance as that of the generalized likelihood ratio test(GLRT).Simulation results show that the proposed method can restrain the strong aircraft signal and detect the weak ARM target signal availably.