Abstract: Based on having generally analyzed multinomial factors including of gas and geology which can bring on the gas-outburs happening,the process of eablishing a universal FTA(fault tree analysis)model for gas-outbur is discussed,and the applying event function of Luling coal mine of Huaibei mining group has been created according to the real geological condition and the recording data of the coal mine.The weightiness coefficient of all basic events of minimal secant collections of the applying FTA model has been calculated and found,which can indicating the degree of the different control factors action to gas-outbur.The methods being applied successfully can offer quantitative basis for marking off gas-geological sections and for forecaing the happening of gas outbur.