The present invention provides a method for preparing rice protein, including treating rice protein powder and water with a combination of a papain and a neutral or alkaline protease. The preparation method of the present invention can improve the solubility of the rice protein, so as to obtain rice protein products with high yield of protein.本發提供一種大米蛋白的製備方法,包括將大米蛋白粉與水,以木瓜蛋白酶及中性或鹼蛋白酶的組合酶解處理,採用本發明的製備方法可改善大米蛋白的溶解度,藉以獲得高蛋白質收率的大米蛋白產品。