Abstract: Coal spontaneous combustion appears in partial positions of Xinjiang Bailitan Open-pit Mine, which caused the surrounding rock lithology changed and became burnt rock by baking and burning. The overall intensity of burnt rock declined compared to original rock, stability is poorer, which seriously affects the stability of the slope. According to the test results, rock physical and mechanical parameters are given, and then, RMR value is corrected combined with engineering analogy method, the reasonable and reliable parameters for numerical simulation are given. GEO-slope software is used to calculate the current slope stability of 1^# typical profile. In the case of natural water level, the minimum slope safety factor is 1.073, less than 1.1, which does not meet the specification. After dewatering and drainage, the minimum slope safety factor is 1.203, which meets the specification.