The invention provides a method for treating slunk. The method comprises the steps of: mainly soaking the slunk with water, coating, liming, deliming, softening, pickling and bating, wherein a coating liquor comprises the components of water, sodium sulfide, sodium hydrosulfide, a liming auxiliary agent and starch; and a liming liquor comprises the components of water, multielement mixed alkali, liming enzyme, sodium sulfide and a liming auxiliary agent. By adding the liming auxiliary agent and the starch in the coating process, the concentration of sodium sulfide is adjusted, the treatment effect on skin slunk grains can be enhanced, a smooth skin surface can be favorably obtained, and the cleanliness of the skin surface is increased; meanwhile, the multielement mixed alkali, in place of lime, can act together with the liming enzyme in the liming process, so that collagen fibers are favorably dispersed and fiber bundles are expanded. As lime is unnecessarily added to the coating and liming processes, the problems of high cost, serious pollution and equipment corrosion brought by lime can be avoided; and as the skin surface of the slunk is tender and susceptible, the problem of damage to the skin surface can be avoided due to no lime addition.