The invention provides a wall scraping device and a method for well flushing and wall scraping. The well flushing wall scraping device comprises a wall scraping device body, an elastic scraper mechanism and a storage sleeve, wherein the wall scraping device body is of a hollow structure, and the elastic scraper mechanism is arranged on the outer wall of the wall scraping device body; the elastic scraper mechanism comprises a scraper, and the scraper is used for expanding in the radial direction under the role of elastic force; and the storage sleeve is further arranged on the outer wall of the wall scraping device body in a sleeving mode and used for sliding in the axial direction under the role of axial force greater than a preset threshold value after wall scraping is completed, so that radial force is applied on the scraper, and the scraper contracts in the radial direction to be stored. According to the wall scraping device and the method for well flushing and wall scraping, scraper recycling is achieved, and accidental stretching of the scraper after the scraper is scraped in an open hole section is avoided, so that wall scraping and well flushing operation can be completed in one tripping process, one tripping operation is reduced, the efficiency of the wall scraping and well flushing operation is effectively improved, and operation cost is reduced.