Convection type pipeline dredger

The invention relates to the technical field of pipeline cleaning devices, in particular to a convection type pipeline dredger. The convection type pipeline dredger comprises a dredging block, pipe sleeves, air pipes and an air pump. The dredging block is plugged into a pipeline. The pipe sleeves are arranged at the two ends of the pipeline in a sleeving manner. The air pump is connected to the pipe sleeves through the air pipes. The dredging block is provided with an ejector head, a seal ring and scrapping teeth. The dredging block is designed and is used in cooperation with the air pump, so that a convection type pipeline dredging mechanism is formed. When the convection type pipeline dredger is used, the dredging block is plugged into the pipeline firstly, then the pipe sleeves are installed at the two ends of the pipeline in a sleeving manner, the air pump alternately inflates the two ends of the pipeline, the dredging block is driven to slide back and forth in the pipeline in the manner that the dredging block is attached to the wall of the pipeline, impurities are removed, sediments on the inner wall are completely removed through the scrapping teeth, it is ensured that no residue exists, and therefore the cleanness degree of dredging is greatly improved.