A method for preparing zinc coating of carbon fiber surface belongs to the material technology field, the method adopts zinc sulfate as main salt, ammonium chloride as electric salt, aluminum sulfate and boric acid as buffering agent, dextrin as dispersing agent and H2O as solvent preparation acidic electroplating solution, the components and the percentage by weight of the electroplating solution are that: the zinc sulfate is 10%-40%, the ammonium chloride is 0.5%-40%, the aluminum sulfate is 1%-5%, the boric acid is 0.5%-3%, the dextrin is 0.5%-3%, the other is H2O. The method comprises the following steps: soaking the treated carbon fiber by the obtained acidic electroplating solution, then electrifying and electroplating the carbon fiber and forming the zinc coating, the thickness of the prepared coating is 2-7mu.m, the coating is plane, homogeneous and uneasy to be peeled off, the carbon fiber of the invention keeps the directionality and configuration as one aspect, simultaneously, the invention improves the soakage of the carbon fiber with basal body in composite material as the other aspect.