The invention discloses a hammer crusher, which is composed of a material inlet, a baffle plate, a mouth guard plate, a casing, a suspension ring, an impact plate, a hammer head, a side guard plate, a rotor disk, a rotor shaft, a front guard plate, and a spacer ring. Sleeve, drive shaft, sieve bar, support sieve plate and bracket, the material inlet is located on the upper right of the casing, the baffle is connected to the inside of the material inlet, the mouth guard is connected to the inner wall of the material inlet, and the lifting ring is connected to the top of the casing , the counterattack plate is connected to the inner wall of the casing, the transmission shaft is connected to the center of the casing, a spacer sleeve is arranged around the transmission shaft, the rotor disc is connected to the spacer sleeve, the side guard plate is connected to the rotor disc, and the four hammer heads are evenly connected to the rotor disc. On the side guard plate, the four hammerheads are respectively connected to the rotor shaft, the front guard plate is connected to the right side of the inside of the casing, the screen bars are connected to the bottom of the inside of the casing, the supporting screen plate is connected to the bottom of the outside of the casing, and the brackets are connected to both sides of the outside of the casing . The invention has the advantages of simple structure, convenient use and reasonable technology.