As the radar bandwidth increases， the energy of a single pulse is dispersed into different range units， resulting in echo splitting. At this time， the signal to noise ratio（SNR） decreases， which is not conducive to target detection. For this problem， an echo phase compensation method is proposed. Taking two scattering points as examples， the echo of scattering points at different relative distances is analyzed to obtain their phase relations. Based on the analysis results， the phase compensation process is carried out for the echo of linear frequency modulation（LFM） signal， and the echo signal scattered in different distance units is accumulated effectively， which improves the SNR and the detection probability. The effectiveness of the method is verified by Monte-Carlo simulations.