Jaw crusher is used for crushing hard raw materials, such as gangue, shale and etc. The motor drive the belt and belt wheel make the trends jaw up-and-down motion by eccentric shaft, the included angle of bracket and trends jaw will become large while the trends jaw moves up, thus to push the trend jaw plate close to the fixed jaw plate, the materials will be crushed at the same time, and the aim of crush is achieved. The ratio of crushing is big, product grain size is uniform, the structure is simple, works reliable and easy to maintain.