In this study, a novel method that integrates the detailed channel two-phase flow into the 3D (threedimensional) model of PEMEC (proton exchange membrane electrolyzer cell) is proposed. We explored the effect of L/GDL (liquid/gas diffusion layer) wettability on the two-phase flow and performance of PEMEC. The results show that in the hydrophilic contact angle range, the more hydrophilic contact angle will deteriorate the performance and hinder the discharge of bubbles to the channel. The novel gradient type L/GDL will further promote the flow of water and gas due to the gradient effect of its wettability. In addition, adding MPL also can improve the two-phase management.