Non-uniform interrupted-Sampling Repeater Jamming is a coherent interference technology based on the principle of undersampling, and it has a salient feature over several uniform interferences in terms of pseudo-randomness, which makes it more difficult for radar to detect real targets. Aiming at the target detection problem of non-uniform interrupted-sampling repeater jamming, a method for radar based on time-frequency domain interference suppression is proposed in this paper. Firstly, according to the short-term Fourier transform strategy, the echo signal is converted to the time-frequency domain, and then we select one of the columns in the time-frequency matrix as the reference column for translating the signal perpendicular to the timeline. Furthermore, the interference distribution area is accurately extracted and filtered out according to the morphological processing. Finally, the simulation results prove that the proposed algorithms have an advantage over non-uniform interrupted-sampling repeater jamming in terms of interference suppression.