The invention relates to the technical field of pipeline systems, and in particular relates to a binding accelerant for protecting an outer erosion resistant layer of a pipeline. The binding accelerant comprises the components in percentage by mass: 25 percent of organic solvents, 15 percent of emulsifying agents, 25 percent of polar materials and 35 percent of deionized water. The binding accelerant is a liquid-stage organic accelerant, which is coated between a 3PE erosion resistant layer of the pipeline and a protective layer, so that the surface tension of the erosion resistant layer can be improved; an active group is embedded into the erosion resistant layer, so that the reaction capability of the PE surface and a functional group of a film forming matter of the protective layer is improved, the adhesion force between the PE surface and the protective layer is enhanced, and the peel resistant strength and the shearing resistant strength between the protective layer and the erosion resistant layer are obviously increased.