Synchronous belt transmission is composed of a root of tooth surface with spacing within weeks of circular belt and with appropriate match round. It combines belt transmission, chain and gear drive their respective advantages. Turns, with toothed wheel tooth mesh to transmit power. Transmission dragon has accurate synchronous belt transmission ratio, no slip, constant speed ratio can be obtained, is stable and can absorb vibration, low noise, large range of transmission ratio, generally can reach 1:10. Allow the linear velocity can reach 50 m/S, the transfer from a few watts to hundred kilowatts. General can reach 98%, high transmission efficiency, compact structure, and is suitable for multiple spindle drive, without lubrication, no pollution, so there is no pollution and can work in environment is relatively bad places. Transmission products are widely used in textile, machine tools, tobacco, communication cable, light industry, chemical industry, metallurgy, instrument, food, mining, oil, automobile and other industries of various types of mechanical transmission.