Abstract: In order to evaluate the coal wall stability of comprehensive mechanized coal mining technology with large mining height, based on the theory of minimum potential energy, the stability analysis model of coal wall was established, the analytical solution of critical slip depth of coal wall was given. The model was applied to Xiegou Coal Mine in Shanxi Province for case verification. The results show that the safety factor of coal wall is related to the slip depth, the height from the center of the circle to the roof and the horizontal thrust of face guard, among them, the horizontal thrust of the face guard plays a significant role in enhancing the stability of coal wall. In addition, the calculated critical slip depth is close to the measured value and the relative error is less than 8%.