Proton exchange membrane fuel cells (PEMFCs) are considered the ultimate solution for new energy power. The gas diffusion layer (GDL) is a key component in PEMFC, serving as electrical conductivity, heat transmission, gas permeability and drainage. Carbon papers (CPs) are currently the preferred commercial material for GDL. Based on wet papermaking, the effect of dispersant, carbon fibers, resin, carbonization and graphitization on the structure and properties of CPs were investigated. The results show that the combination of polyethylene oxide (PEO) and hydroxymethyl cellulose (HMC) is the optimal dispersant system. The best ratio of 6 mm and 3 mm chopped carbon fibers is 80% and 20%, respectively. The vacuum impregnation with phenolic resin can significantly enhance the resin-carbon retention and electrical conductivity of CPs. The increase of carbonization/graphitization temperature is beneficial to the increase of porosity and electrical conductivity of CPs. When the graphitization temperature is 2400 ℃, the porosity of CPs can reach 82.5%, the resistivity is 8.1 mΩ·cm, and the tensile strength is 29.8 MPa.