Tensioning device of heavy sweeper

The invention discloses a tensioning device of a heavy sweeper. The tensioning device comprises a fixed seat, a power twister, a damping sleeve and a screw slippery prevention lead screw, wherein one end of the screw slippery prevention lead screw is connected with a fixed seat shaft, the other end of the screw slippery prevention lead screw is suspended, a power twister base is arranged in a fixed seat hole through the damping sleeve and fixedly connected with the sweeper through a compression bolt in a sleeving mode, and a power twisting arm of the power twister is connected with the screw slippery prevention lead screw in a sleeving mode and fixed through a forward and backward rotation screw slippery prevention regulation nut and a spring. The tensioning device keeps still under high-frequency vibration, so that loss of tensile force caused by looseness of the compression nut is avoided, the blade is attached onto a belt tightly to keep tensile force stable, fatigue damage to a blade base caused by vibration is reduced, and service life of the sweeper is prolonged. The damping sleeve performs secondary buffering on the sweeper to reduce damage to belt fasteners to the minimum extent. By means of the tensioning device, tensioning of a knife edge can be regulated without disassembling the sweeper, and usage and maintenance are more convenient.