The paper makes a quantitative analysis on the range walk of high-speed target and its influence on signal-to-noise ratio in interrupted continuous wave dechirp system. The analysis results show that the difference frequency signal when range walk occurs is a LFM（linear frequency modulation） signal. Aiming at this phenomenon， a time-domain inversion compression compensation method is proposed， which uses the time-frequency characteristics of the signal to generate a time-reversed signal in the time domain， which is conjugated and multiplied with the original signal to remove the frequency modulation slope and realize signal compression. At the same time， a quadratic matched filter compression method is proposed. Based on the speed search information， the frequency modulation slope of the difference frequency signal during range walking is calculated， and the matched filter with the opposite slope is generated. The range walking is eliminated by quadratic matched filtering. It can eliminate the influence of distance walking of high-speed targets， improve the detection power and detection accuracy， and can be applied to the declination system interrupt CW detection radar， which has a good reference significance in the field of high-speed target detection.