The invention discloses a papermaking pulp medium-density fiber grading screen device. The papermaking pulp medium-density fiber grading screen device structurally comprises a top cover, handles, a feed port, a supporting frame, a discharge port, a grading screen main machine and a box door. The upper surface of the top cover is welded to the lower surfaces of the handles. The feed port is embedded in the upper surface of the left end of the grading screen main machine. A raw material is fed from the feed port. The grading screen device conducts rolling on the raw material through cooperationof deviation of a movable jaw plate and immovability of a fixed jaw plate. Through the preliminary rolling treatment, the following screening effect is better. A first-stage belt conducts driving to drive a driving rotary shaft to rotate. At the moment, screening fan blades start to rotate to conduct preliminary screening on the rolled material, so that the screened material is finer. A rotary shaft on a screen drum mechanism rotates to drive screening rotary plates to rotate to conduct further screening on the material. Through operation of a shock absorption mechanism, vibration generated ina screen drum box is reduced, so that operation is more smooth. Thus, the screened material is finer and better.