High-temperature proton exchange membrane fuel cell (HT-PEMFCs) has the advantages of simple hydro-thermal management, strong resistance to CO, direct feeding of reforming gas and high efficiency of cogeneration. It is one of the ideal power sources for the development of clean energy. As the core component of HT-PEMFCs, membrane electrode assembly (MEA) is mainly composed of cathode and anode gas diffusion electrode and proton exchange membrane, which determines the performance and cost of HT-PEMFCs. Therefore, optimizing the structure of gas diffusion electrode (GDE) is an important means to improve the performance and reduce the cost of HT-PEMFC. In this work, from the point of view of catalytic layer, pore-forming agent was introduced into catalytic layer to construct double catalytic layer with different pore structure. Among them, MEA 2 uses 46.7% (w) PtCo/C in the inner catalyst layer without adding pore-forming agent, and the outer catalyst layer uses 40% (w) Pt/C and adds 20% (w) pore-forming agent. It has relatively small ohmic polarization, minimum mass transfer polarization and activation polarization, and has the largest electrochemical active area, and the electrochemical performance is the best. At 160 ℃ and atmospheric pressure, hydrogen and air as fuel, the maximum power density of the single cell composed of the membrane electrode is 439 mW•cm^-2, which is 69 mW•cm^-2 higher than that of the single cell without pore-forming agent. Whether the pore-forming agent is added into the inner catalytic layer (CL) or the outer CL, the pore structure is adjusted to optimize the phosphoric acid (PA) distribution and reduce the oxygen mass transfer resistance to improve the electrochemical performance. The former catalyst layer has a greater hydrophobicity change and the electrochemical performance is more affected by the PA content, while the latter catalyst layer hydrophobicity changes less and the electrochemical performance is more affected by the oxygen mass transfer resistance. Excessive addition of pore-forming agent inside or outside CL will produce larger ohmic polarization resistance (R_Ω), and the acid drowning caused by insufficient hydrophobicity of CL will further reduce the electrochemical performance of the battery.