Addressing the issue of rapid flash-like phase change processes in microporous media and the inadequacy of traditional two-phase zone models, this paper proposes a simplified phase change interface assumption based on the Lee model. Through numerical simulations and experimental studies under high heat flux conditions, it is found that when the mass transfer coefficient γ = 400, the numerical simulation results for water supply flow rates of 700–900 ml/min show the highest agreement with experimental data, with a maximum surface temperature error of less than 1.21%. The study validates the effectiveness of the simplified interface assumption under microporous conditions and reveals the applicability of the Lee model in characterizing rapid gas-liquid phase changes, providing theoretical and experimental support for efficient modeling of microporous transpiration cooling.