Abstract: The angle of the slope is an important factor affecting the safety production of open-pit coal mines.At the same time, increasing the angle of the end slope of open-pit coal mines and reducing the pressure on coal resources by the end slope is of great significance for improving the recovery rate of coal resources.The angle of the eastern slope of the Hongshaquan open-pit coal mine is much lower than the designed slope angle, causing the overlying coal resources on the eastern slope to be unable to be extracted, reducing the resource recovery rate and economic benefits.A comprehensive analysis was conducted on the geological conditions of the eastern slope of the Hongshaquan open-pit coal mine, and combined with the physical and mechanical parameters of the rock and soil and the finite element strength reduction method, we revealed the sliding mode of the eastern slope.The rigid body limit equilibrium method was used to analyze the stability of the typical section of the eastern slope, and the influence of the angle of the end slope on the stability of the slope was explored.The results show that under the current slope section angles of 12°,13° and 14°,the potential sliding modes of the eastern slope sections EB-1 and EB-2 are both circular overall sliding.The maximum shear stress of section EB-3 occurs at the second step of the slope top, and the overall stability coefficients of sections EB-1,EB-2 and EB-3 are 3.560,2.686 and 3.310,respectively, which are higher than the safety reserve coefficient; After optimization, the angles of the EB-1,EB-2 and EB-3 sections of the eastern slope can be increased to 36°,38° and 36°,respectively.The stability coefficient of the slope shows a linear decrease with the increase of slope angle.