Abstract: In this paper, the computational software Plume WorkStation (PWS) is applied to simulate the plume flow field of the main motor of the lunar exploration lander, in order to analyze the plume effects, including the aerodynamic force and the thermal effect of convective heat transfer on the landing buffer mechanism. PWS is a general plume simulation software based on the DSMC method, with loose software architectures to achieve a relative independence of the computation modules, and a two-level construction method to achieve the universality of the boundary conditions. The test case indicates that the simulation results agree well with the experimental results. The simulation applied to the lunar exploration lander demonstrates that the maximum aerodynamic pressure on the landing buffer mechanism, as from the main motor’s plume, is about 2.4 MPa, while the thermal flow of the convective heat transfer reaches the maximum value of about 2 000 W/m2 on the side of the buffer mechanism’s chassis. When the wall temperature increases from 300 K to 500 K, the heat flow of the convective heat transfer on the surface of buffer mechanism reduces slightly, with a varying range of about 5%.