During the developing process of gas reservoirs, different gas well spacing will affect the production of the well and the bottom hole pressure. In this paper, the method of the advanced mechanics of fluids in porous media, the pressure changes into the pesudo-pressure, the changes of the pressure near the well have been obtained. Theoretical model of the gas reservoir has been established, which is built with constant pressure as internal boundary control conditions and infinite formation as outer boundary control conditions. According to the seepage differential equations of the pesudo-pressure, the changes in the production on bottom pressure can be derived in different well spacing. Then the pressure and production curves have been drawn.