The reasons for the yellowing of the tin plating surface are: poor cleaning after plating, formation of water marks, high current density, and high temperature of the liquid helium. In the production of bright tin plating, parts of bright tin plating were encountered, and tin coating yellowed on the surface of parts after being placed in the warehouse for 2 months to 3 months. The analysis found that brighteners used in the acid bright barrel plating process are compounded by surfactants, ketones, aldehydes, organic acids, oxidants, and the like. The column bright additive component was tested and it was found that tin plating on the surface of the plating solution containing the brightening agent in the tin plating solution became yellow after standing for 2 months, and the amount of addition of the optical brightener was found to increase the discoloration time of the tin plating layer. The shorter. As a result, the gloss modifier composition in the brightener is adjusted, and the foregoing electroplating tin failure problem is solved.