Abstract: In order to solve the multiple false targets interference by slicing jamming from Digital Radio Frequency Memory (DRFM), this paper presents a two-step interference suppression method by taking advantage of the difference between slicing jamming signal and target signal in time domain for pulse Doppler radar. Firstly, one-step interference suppression is carried out by particle filter. Abnormal variation of weight from each particle is used to detect jamming signal. Then, the result of one-step filtering is processed by using the negentropy of singular spectrum, which is utilized to suppress small jamming signal. By two-step interference suppression, jamming signal does not match with the matched filter. Finally, the simulation result shows that the proposed method can obtain higher detection probability and has better performance of interference suppression.