Abstract: In order to strengthen the accuracy of Numerical Manifold Method （NMM） for processing large-scale nonlinear dynamics problems， the Numerical Manifold Method with dynamic acceleration is proposed， which takes advantage of explicit integration algorithm for processing large-scale nonlinear problems and extends the characteristics of NMM for processing continuous and discontinuous problems under the same computational framework. The acceleration is defined to change linearly in a single time step， the explicit integration algorithm formula of dynamic acceleration is derived， and the stability test of dynamic acceleration explicit numerical manifold method is carried out. Finally， this method is applied to the stability analysis of an open-pit rock slope. The results show that when the total number of steps and the number of blocks are increased， the advantages of dynamic acceleration explicit numerical manifold method over traditional NMM become more obvious， which further proves the feasibility of this method in dealing with large-scale nonlinear dynamics problems. The slope instability mode of open-pit mine is the upper and middle slide. Considering the thickness of the slope is about 30 m and the actual situation of the slope， it is recommended to reinforce the slope and the instability surface by grouting， so as to enhance its self-bearing capacity to improve its stability and support the slope behind the slope.

Key words: open-pit mine, numerical manifold method, explicit integral algorithm, rock slope, stability analysis