The working principle of the hammer mill is that the material enters the crushing bin, and the powder is impacted by the high-speed rotating grinding knife, mainly by the impact effect to crush the material. The material enters the hammer mill and is crushed by the impact of the high-speed rotating hammer head. The crushed material obtains kinetic energy from the hammer head of the hammer mill and rushes to the baffle and screen bar in the frame body from the high-speed. At the same time, the materials collide with each other and are crushed many times. The materials smaller than the gap of the screen bar are discharged from the gap. Some larger materials are impacted and ground by the hammer again on the screen bar, extruded and crushed, the material is squeezed out of the gap by the hammer head of the hammer breaker to obtain the product of the required particle size. The feed inlet is equipped with a star-shaped blanking valve to control the blanking speed and prevent dust from being generated during the crushing process.