The invention relates to the technical field of dust removal auxiliary devices, in particular to a dust removal device for trash combustion. The effective coverage of water spray on smoke dust is improved, and therefore the dust removal effect is improved, and practicability is improved; the flowing speed of the smoke dust can be evenly distributed, the smoke dust and water spray are prevented from being discharged out of an air outlet pipe under the unstable wind speed, and environmental friendliness is improved; meanwhile, generated sewage can be processed, water resources are saved, and usereliability is improved. The dust removal device comprises a dust removal tower, a water tank, a spraying pump, an air inlet pipe, an induced draft fan, an air outlet pipe, an axial flow fan, a supporting plate, two spraying pipes, a communication pipe, a rotary motor, a ball bearing, a driven gear, a plurality of spraying nozzles, a rotating shaft, a driving gear, two sealing covers, two insertion pipes, a plurality of flow guide plates and a grating plate. The flow guide plates are each of a rhombic structure. The grating plate is evenly provided with multiple groups of wind uniformizing holes. The dust removal device further comprises a sewage pipe, a partition plate, a filter tank, a filtering device and a backflow pipe.