The invention discloses a surface treatment preparation for galvanized steel sheet and a surface pretreatment process, belonging to the technical field of steel sheet surface treatment. First, the surface of the untreated steel sheet is ground and processed, and then further treated with a surface treatment agent. The surface treatment preparation for galvanized steel sheet includes the following raw materials: phosphate ester compound, potassium hydrogen persulfate compound salt, hydrogen sulfate salt, quaternary ammonium aniline compound, sodium carbonate, ammonium acetate, hydroxyethylidene phosphoric acid, imidazoline and its derivatives compounds, acid pickling fog suppressants, alkynyl alcohol derivatives, alcohol ether carboxylates, stabilizers, chelating agents, water. The surface treatment preparation for galvanized steel plate provided by the technical solution of the present invention can effectively remove oil stains, oxide films, rust spots and other adhesive impurities on the surface of the steel plate. Volatile substances, wastewater treatment is simple, safe and environmentally friendly. After the steel sheet is treated as above, it helps to improve the quality and efficiency of the galvanized steel sheet.