Abstract: In view of the shape design of the boundary slope of the soil-rock composite reverse dip slope in the open-pit mine，the landslide model and stability of soil rock composite reverse dip slope in Dalianhe Open-pit Coal Mine is studied by adopting the method of rigid body limit equilibrium and three-dimensional numerical simulation.The study is based on the engineering practice of the compound reverse dip slope of the north slope of outer dump and the top slope of the stope in Dalianhe open-pit coal mine，by which the safety of the mining of coal resources of the north to boundary slope is guaranteed.The study results show that for the compound reverse dip slope of the north slope of outer dump and the top slope of the stope in Dalianhe open-pit coal mine，the landslide model is circular sliding；in order to meet the safety requirements，the mining slope angle should be up to 33°；the failure form of rock mass is the composition of tension and shear.At the foot of slope，local rock mass destruction should be done due to the stress concentration caused by the rock mass weight and it is the inducing factor of the whole slope failure.

Key words: Composite slope, Reverse dip slope, Slope stability, Shape optimization