The echo waveform is one of the core data from the laser altimetry satellite, and the simulation analysis of echo waveform has important reference value in parameters designing and data processing for the satellite. In this paper, the effects of three factors such as ground reflectivity, emission waveform and laser profile array (LPA) on the echo simulation results are considered, and the contrast experiment is conducted. The optimal simulation method is discussed. In the experiment, a certain research area is selected, and the data of ice, cloud and land elevation satellite (ICESat)/geo-science laser altimeter system (GLAS) is used as the verification data, and the echo simulation accuracy is evaluated by the correlation coefficients. The results show that the echo simulation accuracy can be significantly improved after the actual ground reflectivity and emission waveform are considered, and the correlation coefficient of the simulation results is improved from 0.9337 to 0.9492. Due to the low spatial resolution of the pixels in the LPA, there exists a large error in simulation accuracy. With the increase of pixel resolution by cubic spline interpolation, the simulation accuracy can be improved to 0.9513.