There are many high and steep slopes on the Moon, whose slope angles are usually larger than 30°. The maximum slope angle may reach 48.9° on the lunar mare and 55.7° on the lunar highland. These steep slopes will seriously affect the safety of the future lunar exploitation , such as the in situ resource utilization. By implanting a new microscopic model considering rolling resistance and van der Waals forces, two-dimensional simulations of lunar soil landslide tests were carried out at different initial slope angles using discrete elemt method. The effects of the initial slope angle on landslide mechanism and engineering disaster indexes were analyzed. The results show that with a certain rear slope volume, the maximum flow distance increases with the increase of the initial cut slope angle while the final stable slope angle seems unaffected by the initial cut slope angle. During the landslide process, the slope with slope angle lower than 60° mainly fails in a flow mode while the slope fails in a collapse mode when the slope angle is larger than 60°. In addition, the maximum slide speed increases in a parabolic ways with the increase of initial slope angle.