Multi-layer filtering mechanism for battery laser die cutting dust removal and purification air return device

The invention relates to the technical field of battery manufacturing, and discloses a multi-layer filtering mechanism for a battery laser die cutting dust removal and purification air return device, the multi-layer filtering mechanism comprises a ventilation pipe, the ventilation pipe is fixedly communicated with a replacement box, the replacement box is internally provided with a filter screen, and the ventilation pipe is internally provided with a transmission assembly for power transmission through wind power; a replacement assembly used for replacing the filter screen and preventing dust accumulation is arranged in the replacement box, a connecting assembly used for assisting the filter screen to rotate is arranged in the replacement assembly, and a second tooth block moves upwards under the action of magnetic attraction and is meshed with a first tooth block, so that the filter screen can be replaced when the accumulated dust is sufficient; when effective filtering cannot be carried out, automatic repla