The invention discloses a technique for manufacturing a pneumatic wing plate for a bridge. A pneumatic wing plate envelope for the bridge consists of a polyphenylene sulfide ether resin composite material which mainly comprises the following main components in percentage by weight: 50 to 55 percent of polyphenylene sulfide ether resin, 3 to 5 percent of random ethylene-acrylic ester-glycidyl methacrylate terpolymer, 2 to 5 percent of random ethylene-glycidyl methacrylate dipolymer, 35 to 40 percent of glass fiber, 50 to 55 percent of polyphenylene sulfide ether resin, 3 to 5 percent of random ethylene-acrylic ester-glycidyl methacrylate terpolymer and 2 to 5 percent of random ethylene-glycidyl methacrylate dipolymer. After the components are mixed in a dry state, the injection molding of the envelope is completed by using a homodromous double-screw multi-gating hot-runner mold. The technique solves the deformation problem of the wing plate envelope well, improves the manufacturing efficiency and lowers the production cost on the premise of ensuring that the wing plate has enough intensity.