Abstract: This paper put forward the risk assessment method of major accidents in coal mine,such as gas and coal dust explosion accidents,fire accidents and flood accidents,conducted risk assessment on major accidents in coal mine by using the method of index evaluation,designed "the risk assessment table of flood accidents in coal mine" and "the risk assessment table of gas and coal dust explosion accidents and fire accidents in coal mine",presented the methods and steps of the risk assessment on major accidents in coal mine,and developed the matching software system based on B/S model in order to conduct the work such as risk assessment on major accidents in coal mine,early warning of risk and optimization of safety countermeasures on the LAN of coal mining enterprises.The research results have been applied in Xiezhuang Coal Mine successfully,and have achieved good social benefits.