Suction machine is mainly made up of working bridge, drive device, central support, transmission vertical frame, scraper arm, mud plate, suction pipe, center set mud trough and skimming device. Along both sides of the scraper is arranged in a symmetrical arrangement of suction pipe, each suction pipe from the system, not interfere with each other, from the suction port directly through the mud tank. The wiper arm rotation, by the mud collecting board the sludge suction pipe to guide, use the water level difference self absorption, while turning edge suction. When the sludge is collected in the collection, the sludge is discharged into the pool. The surface of the dross by slag skimming plate into the left bucket.