The invention discloses a grading filter, which comprises a feeding cylinder body, a filtering cylinder body and a reflux rinsing cylinder body, wherein the feeding cylinder body, the filtering cylinder body and the reflux rinsing cylinder body are sequentially, fixedly and integrally arranged, a first-stage filtering screen cylinder, a second-stage filtering screen, a flow stabilizing filtering screen and a one-way flow passing member are sequentially fixed in the filtering cylinder body at intervals, the side portion of the filtering cylinder body is provided with a material outlet, and a motor and a stirring shaft connected to the rotating shaft of the motor are arranged in the feeding cylinder body. According to the present invention, the grading filter has characteristics of simple structure, convenient operation, reliability, high filtering efficiency and long service life; and with the grading filter, the material is pure through the grading filtering, and the bridging phenomenon of the stirring shaft at the medium channel inlet can be avoided during the filtering, such that the small particles are blocked and are deposited on the surface of the medium to form the filter cake.