Abstract: In the presence of the strong scattering sources, the spectrum has spread throughout the frequency domain of the return signal, resulting in the challenge of detecting weak target for the linear frequency modulated continuous wave (LFWCW) radar system. Based on the relevance analysis among the multi-frame difference-frequency signals derived from the neighboring region of target direction, the weak target feature enhancement technology based on the multi-frame processing jointly is proposed through weighting method of compensation in range dimension. Then, the multi-frame joint procession is carried out to promote the detecting capability for the weak target with return signal feature enhancement. Finally, the analysis results of experimental data from a foreign matter detection radar shows that the clutter suppression can be effectively conducted by the proposed algorithm.