The invention relates to a method for presorting restaurant kitchen waste through a wet process. The method for presorting restaurant kitchen waste through a wet process comprises the steps of feeding, cleaning and filtering purification, so that restaurant kitchen garbage is presorted through the wet process, wherein crude waste does not have to be sorted and pulverized, and the operating cost is greatly reduced. Not only is the restaurant kitchen waste safely and efficiently recycled, but also harmless treatment is realized, the harm of swill is stopped from the source, and the problem of resource shortage in China can be relieved.