Small jaw crusher mainly consists of frame, eccentric shaft, jaw plate, connecting bar, adjustment part and spring.The movable jaw goes upward and downward through eccentric shaft when belt and belt wheel are driven by the motor. The angle between movable jaw and bracket turns big when the movable jaw goes upward, which pushes the movable jaw plate to come closely to fixed jaw plate. At the same time, materials are crushed with the movement of the movable jaw. When the movable jaw goes downward, the angle between movable jaw and bracket turns small. Under the force of spring and connecting bars, the movable jaw plate leaves fixed jaw plate, and the crushed materials with qualified size are discharged from the crushing cavity. With the continuous rotation of the motor, the movable jaw crushes and discharges materials, which, in turn, realizes the goal of mass production.