It is very important to study the effect of gas-water two-phase seepage on the gas well productivity in gas-water two-phase seepage flow, which is an important problem in gas reservoir development. Based on the theory of multi-phase percolation of fluids in the formation, a mathematical model is established to solve the seepage differential equation of gas-water two-phase flow. The non-Darcy effect and skin factor are deduced. Gas-water two-phase productivity formula, the relationship between pressure and pseudo-pressure under different water-vapor ratio conditions was analyzed. The calculated results show that with the increase of water - gas ratio, the open - flow of gas wells decreases, and the decrease of water - gas ratio is significant to gas reservoir development. The analysis of gas-water two-phase seepage mechanism and productivity can provide guidance for the analysis of gas-water production.