The invention relates to a welding fume purifier with a self-cleaning function based on the internet of things. The welding fume purifier comprises a shell, a first air inlet pipe, a connecting mechanism, a dust suction inlet, a cleaning mechanism, a filtering mechanism and a base. The filtering mechanism comprises a filter layer, a second air inlet pipe, a fan, an air outlet pipe and an air outlet. The cleaning mechanism comprises a brush, a movable rod, a groove, a first motor, a first driving shaft, a steel wire rope and a pulley. The connecting mechanism comprises a supporting frame, a driving assembly and two clamping assemblies. The driving assembly comprises a sliding block, a second driving shaft, a second motor and a first transfer rod. According to the welding fume purifier with the self-cleaning function based on the internet of things, the first air inlet pipe can be disassembled through the connecting mechanism, the stability of the welding fume purifier motion process is improved, the operation risk is lowered, the filtering layer is cleaned through the cleaning mechanism, the purifying effect is improved, the time of artificial cleaning is shortened, and the working efficiency is improved.