Abstract: For long-distance aircraft targets, airborne multi pulse laser rangefinders usually adopt digital processing system. The factors that affect the ranging accuracy include the range resolution of emitting laser pulse width, the waveform broadening caused by atmospheric propagation and target reflection characteristics, the nonlinear phase frequency characteristics of echo signal receiving and processing channel, etc. Digital sampling rate, echo signal denoising and target waveform peak point position estimation usually cause large target range positioning error. In this paper, an echo denoising method based on Empirical Mode Decomposition(EMD) and reconstruction was proposed. Firstly, the echo waveform of pulse laser target was modeled, and then the performance of existing digital echo denoising algorithms and its influence on positioning accuracy were analyzed. The experimental results show that the proposed method can accurately extract the target peak point position and improve the target positioning accuracy of laser rangefinder.