Abstract: In the light of current severe safety situation of coal industry, and based on the classification study on safety investment by domestic and overseas scholars, the paper puts forward index system and subdivision elements of safety investment index for coal producing enterprise. In order to optimize the safety investment and inhibit accident loss, the paper constructs a mathematical model of comprehensive importance degree on safety investment index in coal producing enterprise. Finally, a specific example is given to diagnose comprehensive importance degree on its indexes，which provides a reasonable allocation of safe investment for the future of coal production enterprises.