Repair the grooves and holes in the wall. Clean the dust and sundries in the groove or hole with scraper and brush, smooth the edge of the groove or hole with sandpaper or grinding head, apply wall treatment agent or putty in the groove or hole to make it fully penetrate into the groove or hole, fill the groove or hole with caulking agent, compact it with scraper to make it flush with the wall surface, polish the surface of caulking agent with sandpaper to be consistent with the surrounding wall surface, and then apply wall paint after it is repaired thoroughly, so that the repaired part can be around.