The invention discloses a sizing agent circulating filtration and use device for a coating machine. The sizing agent circulating filtration and use device comprises a filter body, a collection tank, a return tank and a scraping plate. The filter body is internally provided with a filter element, the lower end of the filter body is connected with a feeding pipe, a power pump is arranged between the feeding pipe and the filter body, the other end of the filter body is connected with a return pipe, a discharging pipe is arranged at the upper end of the return pipe, a flowmeter is arranged in the discharging pipe, and an alarm lamp is arranged on the exterior of the discharging pipe. The exteriors of a scraper blade and a base material of the coating machine are fixedly provided with a fixing plate, the two sides of the fixing plate are provided with adjusting threaded rods, the adjusting threaded rods are internally connected with the scraping plate, the lower end of the fixing plate is connected with the collection tank, the lower end of the collection tank is connected with a pipeline, the other end of the pipeline is connected with the return tank, the return tank is internally provided with the return pump, and the return pump is connected with the filter body through the return pipe. The sizing agent circulating filtration and use device recycles the surplus sizing agent used during coating, and the sizing agent is saved.