The invention relates to a method for preparing rice protein with high dissolubility, and belongs to the technical field of deep machining of plant protein resource. The method uses broken rice as a raw material; and the rice protein separated out by an alkaline extraction and acid precipitation method is subject to working procedures of compound enzyme multi-locus directed modification, graft copolymerization with amylose, spraying, drying and the like to prepare the rice protein with high dissolubility. The nitrogen solubility index NSI of the rice protein prepared by the method is more than or equal to 85 percent; and the rice protein can be widely used as a functional ingredient of a protein beverage, a roasted product, a minced meat product and a nutritional health-care product.