At the aspect of time of flight (TOF) based laser ranging, the interference pulse is superimposed on the rising edge of signal pulse, so the classic double-threshold processing algorithm cannot correct the identification error of pulse front time. In this paper, a dynamic multi-threshold fitting error correction algorithm is proposed. By switching three thresholds dynamically, the best fitting method is found to avoid the wrong fitting correction result caused by the interference pulse. In addition, a new concept of threshold time difference correlation curve is proposed, which adjusts the threshold dynamically according to the deviation degree between correction point and correlation curve. The experimental results show that the proposed dynamic multi-threshold error correction method can obtain ideal correction results, allows incorrect data to be filtered out, so as to improve the ranging accuracy of long-range targets.