Abstract: In order to deal with noise interference on time-phase modulation (TPM) signals, a frequency shift filtering method is proposed based on recursive least-square(RLS)algorithm by using non-stationary signal processing method and spectral characteristic of TPM.At the same time,the way of removing interferences which show cycle stationary characteristic is discussed,and the filter diagrams of these two filtering methods are presented.Finally, the performance of the filtering method is simulated and compared.The simulation shows that frequency shift filtering method of TPM based on RLS algorithm can suppress noises effectively, and the power requirement probably decreases 3 dB when the BER is equal to 10^-5.