The invention relates to a pre-tightening, anti-loosening and balancing device for a spiral rotating shaft. The device comprises the spiral rotating shaft, a worm gear, a worm, a first rotating shaftseat body and a second rotating shaft seat body, wherein a spiral groove is formed in the middle of the spiral rotating shaft, a steel wire is wound on the spiral groove, an innermost end of the steelwire penetrates into the spiral rotating shaft and is fixed on a
steel ball, a cylindrical shaft is arranged at one end of the spiral rotating shaft, a platform is arranged on the other end, a worm wheel with a platform inner hole is arranged on the platform shaft in a sleeving mode, the worm is arranged on the outer side of the worm gear and assembled in a worm mounting hole in the second rotating shaft seat body, an annular groove is formed at a
tail end of the worm, a screw mounting hole is formed in the position, right opposite to the annular groove, of the second rotating shaft seat body, and a
set screw is assembled in the screw mounting hole. The device has the advantages that pre-tightening design is added in a transmission mechanism of a steel
wire rope through the spiral rotating shaft, so the steel
wire rope is pre-tightened, the locking design of the
tail end position of the worm is added, and a phenomenon that the steel
wire rope is loosened due to self-rotation of the spiral rotating shaft caused by worm and gear matching loosening is prevented.