The invention discloses a protection cover device for a liquid static spraying gun. The liquid static spraying gun comprises a gun body and a nozzle, and the nozzle is in threaded connection with an anti-collision sleeve. A threaded hole allowing the nozzle to be inserted in is formed in the anti-collision sleeve, and a plug for sealing the anti-collision sleeve is arranged at one end of the anti-collision sleeve. A connecting block is arranged at one end of the plug, and a plurality of connecting clamping strips are arranged on the connecting block in a circumferential array manner. A plurality of limiting sliding channel grooves allowing the connecting clamping strips to be embedded in a sliding manner are formed in the surface of the outer circumference of the anti-collision sleeve, anda through hole allowing the plug to penetrate is formed in the connecting block. A pair of sliding grooves is formed in the inner circumferential wall of the through hole in a mirroring manner, and apair of limiting blocks embedded into the sliding grooves in a sliding manner is arranged on the surface of the outer circumference of the plug in a mirroring manner. The limiting blocks are fixedlyconnected in the sliding grooves through connecting springs, and the position, away from the limiting blocks, of the surface of the outer circumference of the plug is wrapped by a water absorption cotton cloth layer. After the plug is mounted on the anti-collision sleeve, part of the water absorption cotton cloth layer is in contact with the outside. The protection cover device can achieve an anti-collision protection function on the nozzle, and meanwhile the blocking phenomenon of dust is avoided.