The invention provides a system and method capable of increasing a protein extraction effect. The system comprises a stirring tank and crushing equipment a, wherein the lower end of the stirring tankcommunicates with a feed opening of the upper end of the crushing equipment a through a pipeline, a valve is arranged on the pipeline, a stirring device is arranged in the stirring tank, and a feed opening is formed in the upper part of the stirring tank; and a discharge opening is formed in the crushing equipment a. According to the system and the method, the particle diameter of protein can be effectively reduced, the protein dissolving and extraction efficiency is improved, the protein extraction time is shortened, the residual amount of protein in bean dregs is reduced, the stability of the protein particles is improved, and besides, the water consumption during protein extraction is reduced.