In dense traffic environments, the simultaneous operation of multiple Frequency Modulated Continuous Wave (FMCW) radars can introduce serious mutual interference problems, resulting in energy mutations and false targets in the radar echo signals, which affects the accuracy of target detection and parameter estimation. This article proposes a non-coherent interference suppression method based on time-frequency analysis and constant false alarm detection (CFAR) for non-coherent interference scenarios. This method first performs Short Time Fourier Transform (STFT) on the received intermediate frequency signal to obtain high-resolution time-frequency spectra; Then, one-dimensional CFAR is used to detect and identify the interfered time-frequency units, and the energy information of neighboring normal units are used to repair the interfering units; Finally, the suppressed signal is subjected to multidimensional Fast Fourier Transform (FFT) processing to obtain distance, velocity, and angle information. The experimental results show that this method can effectively identify and suppress incoherent interference caused by FMCW signals with different slopes, significantly improving the target signal-to-noise ratio and detection performance.