Close the corner plug door, remove the air duct and lift the hook. The construction of large-scale road maintenance machinery is a professional team for line maintenance. It undertakes the long-term tamping, construction and flaw detection of lines and turnouts, and it should be carried out through the operation procedures of closing the door at one corner, dismantling the air duct at the other end and lifting the hook at the third end. The construction work of large-scale road maintenance machinery mainly includes: track replacement by sections, ballast removal of sleepers, ballast replacement, renovation of subgrade frost boiling sections, starting, shifting, tamping of tracks and turnouts after operation, tamping of track ballast shoulders, stabilization, ballast pressing and shaping.