The invention discloses a multistage crusher. The multistage crusher comprises a barrel-shaped shell, a feed opening is formed in the upper end of the shell, a discharge opening is formed in the lower end of the shell, the inner wall of the shell is provided with a lining plate, the lining plate is provided with multiple layers of annular partition plates, a crushing cavity only with the inner annular face opened is formed by the two adjacent partition plates and the lining plate in an enclosure mode, and at least one baffle is vertically arranged in each crushing cavity; a central rotating shaft extending up and down is installed in the shell, a rotating shaft sleeve or a hammer disc which coaxially rotates with the central rotating shaft is arranged on the central rotating shaft in a sleeving mode, hammering heads are installed on the rotating shaft sleeve or the hammer disc, each hammering head extends into the corresponding crushing cavity, and the crushing cavity on each layer at least corresponds to one hammering head; the hammering heads hit materials into the crushing cavities, the materials impact with the lining plate, the partition plates and the baffles in the crushing cavities, and meanwhile the materials mutually impact for crushing; the crushed materials enter the crushing cavity on the next layer for another time impacting till the materials are discharged out of the discharge opening. The phenomenon that the materials are in the crushing cavity on the same layer and do not fall into the crushing cavity on the next layer along with movement of the hammering heads is avoided.