Abstract: Under the action of mining disturbance, the internal unloading fissures of slope in surface mine develop continuously, which will directly lead to the deterioration of the overburden mechanical strength parameters of the slope. In this paper, based on the constitutive model of rock mass deterioration, the mechanical state of slope rock mass is judged through mechanical calculation, and the mechanical strength parameter value of rock mass is automatically obtained, then the dynamic real-time evaluation of slope stability is carried out by strength reduction method. Taking the expansion extraction of high and steep slope in Qidashan Surface Mine of Ansteel Mining Group Co., Ltd., as the engineering background, combined with the GPS deformation observation data of the slope, the displacement of the slope and the dynamic safety factor are one-to-one corresponded. A set of safety factor dynamic evaluation method based on slope deformation is established by using neural network and numerical simulation, which can realize real-time warning of slope.