The utility model relates to a cover tube cleaning tool that oilfield workover used, in particular to casing pipe scraper. Install three cutting edge on the device's the scraper body middle part outer wall, it has a plurality of tungsten steel alloy posts to inlay on every cutting edge outer wall, and the cutting edge inboard is equipped with the piston, and be sealed through the sealing washer in the piston slide of piston cartridge on scraper body lateral wall, is equipped with the spring holder on the step face of cutting edge both ends respectively, and cutting edge both ends step is arranged in respectively in two recesses on the scraper body lateral wall. The utility model discloses a scraping the sharpener and totally near on set inside pipe wall, scraping effectually and do not damage the sleeve pipe body, work efficiency is high, does not have under the circumstances that the fluid passes through at the instrument, scrapes the sharpener to withdraw inside tool body, makes it very easily through casing deformation position and the difficult sticking of tool accident that takes place, and instrument spare part is few, and simple structure is equitable, uses safe and reliable.