The invention discloses a water-retaining and sterilizing coating solution for mango, which is composed of shellac, monoglyceride, sodium carbonate, myristic acid, aminooxyacetic acid and a solvent, wherein the mass concentration of shellac is 15-20%, and the single The mass concentration of glyceride is 0.1-0.2%, the mass concentration of sodium carbonate is 0.3-0.5%, the mass concentration of myristic acid is 0.002-0.004%, and the mass concentration of aminooxyacetic acid is 0.001-0.002%. The invention can reduce the fresh-keeping cost, does not produce cold-resistant pathogenic bacteria, can inhibit the respiration of mango and the growth of surface pathogenic bacteria, and prevent rot. The water-retaining and sterilizing coating solution is stable and can be stored for half a year without deterioration. The water-retaining and sterilizing coating liquid of the present invention can make the surface of mango bright, and after 100 days, the bad fruit rate is less than 5%, the water loss rate is less than 10%, and the taste is kept fresh.