The special primer for concrete base surface is a two-component base coating material containing a small amount of solvent in the epoxy resin amine curing system. It can be used as a base coating material to enhance the adhesion of polyurea and other coating systems, and can also be used as a caulking and filling material (with powder) and a base surface repair layer (with quartz sand). This layer of paint can improve the flatness, thickness and strength of the entire polyurea coating system.