Abstract: In order to evaluate safety of protective bench in north end slope of Haerwusu open-pit Coal Mine, the basic information of the fault in northern end slope is determined according to the analysis of geological survey and data. According to the geometric and geological structure of protective bench in north end slope of Haerwusu open-pit Coal Mine, the stability of the slope is analyzed by numerical simulation and the result shows that the coefficient of stability with two-dimensional modeling is 1.452 (the coefficient is 1.262, considering the influence of vibration), and the coefficient of stability with three-dimensional modeling is 1.75; after mining the protective bench, the angle of north end slope increases from 34 degrees to 36 degrees, the coefficient of stability reduces to 1.413 (the coefficient of stability is 1.221, considering the influence of vibration), the coefficient of stability with three-dimensional modeling reduces to 1.63, which meets the safe requirements for the long-term. The dangerous sources can be controlled and eliminated by clearing the pumice, hanging nets, blocking stone and retaining walls and stone netting. In addition, controlling blasting and drainage can reduce the formation of dangerous sources and ensure the safety of people and equipment during mining the protective bench.