The invention belongs to the technical field of machine parts and particularly discloses a conveyor belt sweeping device. The conveyor belt sweeping device comprises a base and a floating roll. A plurality of scraper units are evenly distributed on the floating roll in the circumferential direction, and the floating roll is connected to the base in a vertical floating mode through a supporting mechanism. Each scraper unit comprises a scraper and a scraper clearing mechanism for clearing debris adhering to the scraper. Each scraper clearing mechanism comprises a sealed pipeline fixedly connected to the floating roll in the circumferential direction, and the sealed pipelines are opened away from the center of the floating roll in the circumferential direction of the floating roll. Openings of the sealed pipelines are sealed and slidably connected with driving sliding blocks and driven sliding blocks correspondingly, with rotation of the floating roll, the driving sliding blocks are extruded by a conveyor belt firstly to slide towards the center of the floating roll, and the driving sliding blocks and the driven sliding blocks are connected with the bottoms of the sealed pipelines through springs. According to the conveyor belt sweeping device, the good sweeping effect is ensured through the scrapers all the time.