The invention relates to a 
pulley protection device of a stage hanging steel 
wire rope. The 
pulley protection device comprises a bottom mounting plate, side mounting plates and a long shaft connectedto the side mounting plates, wherein a cone 
pulley is mounted on the long shaft; the cone pulley is fixedly connected with a 
flywheel mechanism which performs centrifugal motion; guide blocks are fixed to the side mounting plate on the side close to the 
flywheel mechanism; conical arc surfaces of which the 
radius is gradually increased are arranged on the guide blocks; a plurality of 
rope groovesare uniformly distributed in the cone pulley along the axis; and the 
flywheel mechanism comprises a rotary disc, swinging blocks which are hinged to the rotary disc and are uniformly distributed, andsprings of which one ends are connected with the rotary disc and the other ends are connected with the swinging blocks. According to the pulley protection device, the pulley of a conical structure isadopted, so that the 
bearing capacity of the pulley is greatly strengthened, abrasion of the pulley in the same position is effectively reduced, the pulley structure is prevented from being broken, the pulley can be subjected to self-adaptive adjustment according to the speed of the steel 
wire rope, manual maintenance is not required, the service life of the pulley is prolonged, the occurrence possibility of security accidents of the hanging steel 
wire rope is decreased, and maintenance cost of a theater is reduced.