Abstract: High water-containing tight condensate gas reservoirs are characterized by tight reservoirs with low porosity and high water saturation. During the development process, when the pressure drops below the dew point pressure, the fluid will undergo complex phase behavior, precipitate condensate and form the three phase percolation of oil, gas and water, which leads to a further increase in percolation resistance. Compared with conventional condensate gas reservoirs, the phase behavior in high water-containing tight condensate gas reservoirs have the particularity during development. First, the water saturation of reservoirs is high, and the water phase will affect the phase behavior of fluids; second, due to the tight reservoir, complex fluids, high percolation resistance near the bottom hole and steep pressure drop funnel, the fluids show strong non-equilibrium phase transition, which is obviously different from the equilibrium phase transition in conventional condensate gas reservoirs. Based on the laboratory experiment of PVT cell, the long core displacement experiment and the theory of non-equilibrium phase, this paper systematically analyzes the special law of phase transition in high water -containing tight condensate gas reservoirs. The results show that:(1) the water phase will reduce the dew point pressure of the condensate gas reservoir and increase the retrograde gas condensate saturation; (2) there is a lag in gas condensation in the condensate gas reservoir, and the non-equilibrium phase behavior effect can reduce the condensate saturation;(3) for the gas wells less affected by formation water, more gas condensate can be produced by increasing the production pressure difference. Thus, according to the characteristics of special phase behavior, this can provide a basis for determining a reasonable production pressure difference for the exploration of high water-containing tight condensate gas reservoirs.