The invention discloses a material rasping machine with an adjustable output opening. The material rasping machine comprises a rasping machine casing, wherein a rasping mechanism is arranged in the rasping machine casing; a first material blocking plate, a second material blocking plate and a third material blocking plate are arranged between the rasping mechanism and the rasping machine casing; one end surface of the rasping machine casing is provided with an installing hole; the side surface is provided with three arc-shaped regulating holes and a plurality of discharging holes; the raspingmechanism comprises a rotating shaft matched with the installing hole; a plurality of material blocking discs are distributed on the rotating shaft in an array manner; a support frame is arranged between the adjacent material blocking discs; the support frame comprises four connecting rods; crushing tubes are arranged on the connecting rod; the first material blocking plate, the second material blocking plate and the third material blocking plate are all telescopic arc-shaped plates. Through the matching among the material blocking plates and the telescopic regulation functions, the regulationof different material discharging openings can be realized; the requirements of different material discharging occasions can be met; through the structural designs of the material blocking discs, thesupport frame and the crushing tubes, the materials can be sufficiently ground; the material crushing and processing efficiency can be improved.