Underground engineering poison filtering, ventilation and oxygen enrichment air supply system and method

The invention belongs to the technical field of air separation, and discloses an underground engineering poison filtering, ventilation and oxygen enrichment air supply system and method.The underground engineering poison filtering, ventilation and oxygen enrichment air supply system comprises a filtering absorber and an air separation device; gas firstly passes through the filtering absorber and then enters the air separation device, the filtering absorber is used for filtering poisonous gas, the air separation device comprises an adsorption separation module, and nitrogen and oxygen are separated from the gas input into the adsorption separation module; oxygen separated by the adsorption separation module is conveyed to personnel or equipment needing oxygen through a first output pipeline; the separated nitrogen is conveyed to equipment needing the nitrogen through a second output pipeline; the adsorption separation module comprises an adsorption tower; the gas enters an adsorption tower, and nitrogen-rich a