Abstract: In the percolation process of a gas reservoir with high CO2 and H2S, gas will escape from water or water will separate out from gas, which always changes the gas reservoir flowing performance. This paper presents the gas?water percolation mathematic model based on the seepage mechanics theory, combining with mass conservation equation and considering the dissolution and volatilization of gas and water in the reservoir, by which the deliverability equation influenced by 4 parameters of laminar coefficient, turbulence factor, gas?soluble water coefficient and water?soluble gas coefficient is deduced thereby. Also, the comprehensive seepage model for calculating the gas?water relative permeability curve, single well controlled reserves and water influx intensity is developed by means of relative permeability equation and pressure drop equation for water drive gas reservoir. Through auto ?matching analysis of gas production, water production and tubing and casing pressure of gas well, above 4 parameters can be obtained by this auto?matching method. This new method can get rid of the limitation of relying on field well testing to determine a gas well productivity