Grinder and grinding method

The invention provides a grinder which is provided with a plurality of parallel rotary shafts; grinding discs arrayed at intervals are mounted on each of the rotary shafts; the disc surfaces and the peripheral surfaces of the grinding discs are grinding surfaces; the grinding discs of every two adjacent rotary shafts are inserted in each other's grinding disc intervals; and the clearance between the disc surfaces of two adjacent grinding discs not on the same rotary shaft and the clearance between the peripheral surface of the grinding disc and an adjacent rotary shaft form a grinding area forgrinding material. The invention further provides a grinding method. A plurality of grinding discs are utilized to form a large-area grinding processing surface, and the grinding surface of each grinding disc is utilized to grind material. The grinder has the following advantages: the material distributed on the large-area grinding processing surface can be effectively ground no matter the watercontent or oil content of