Abstract: ‍ ‍In order to effectively suppress dense false target jamming by coherent radar， a jamming suppression algorithm based on slope varying combined with BFT（Biorthogonal Fourier Transform）is proposed. Under the condition of self-defense jamming， the radar transmits slope varying LFM（linear frequency modulation） waveform and receives 1 coherent processing interval echo and process it. Firstly， the average delay of echoes in the interfered segment is estimated by matching correlation operation， and the part of the echo that was disturbed are intercepted according to the delay. Secondly， the echo signal is converted to the slope domain by Biorthogonal Fourier Transform， and the difference of the slope is used to separate the real target echo from the interference signal， and a filter windows is designed in the frequency modulation slope domain to cover the position of the interference peaks； Then， the real target echo is recovered by IBFT（Inverse Biorthogonal Fourier Transform）； Finally， pulse compression and coherent accumulation are used to further suppress jamming. The feasibility of the method and its effectiveness in different scenarios are verified through simulation experiments. After interference suppression， the detection probability of real targets is greatly improved.The effectiveness analysis results show that the detection probability of real targets is greatly improved after interference suppression， and the algorithm has advantages in dealing with scenes with a large number of false targets.