Abstract: In recent years, the mining activities of Chengchao Iron Mine have caused a large area of surface deformation and failure. In order to protect the property and life safety of the mining area, it is necessary to timely warn the surface deformation and failure. Firstly, seven influence factors, such as original rock stress, effective thickness of orebody, overlayer properties, stability of quarry headplate, ground water, main scope of impact angle and regional fault instability were selected as the evaluation indices, and the improved entropy weight method was used to calculate the weight coefficient of each evaluation index. Based on the principle of efficacy coefficient method, an early warning analysis model of deep mining surface deformation and failure was established. Taking four typical surface deformation damage disasters in Chengchao Iron Mines as an example, the early warning model was verified, and the early warning results were consistent with the actual situation, indicating that the early warning model based on efficacy coefficient method has high feasibility and science, and can provide some guidance for the early warning of surface deformation and failure in mining areas.