Abstract: This paper took the burnt rock in No.2 mining area of Bailitan Open-pit Coal Mine as the research object, selected the typical section for stability analysis and optimized the final slope angle based on the analysis results. The results showed that the slope angles of section 1 and section 2 remain stable at 34° and 36° respectively in natural state, and in underground dredging and draining condition, the slope angle of section 3 remains stable at 32°; take the safety factor of 1.15 as the safety standard, in the case of underground dredging and draining works in place, the slope angle of section 3 could be increased to 33° to 34°, and section 1 could be increased to 36°.