The invention discloses a municipal 
sludge drying tail gas treatment device and method. The device comprises a 
drying device, wherein an air outlet of the 
drying device is connected with a 
cyclone dust collector, the 
tail gas generated after dedusting sequentially passes a bath 
tower, an alkaline 
tower and a 
biological filter and is sucked and exhausted through an induced draft fan, the air outlet of the drying device is connected with an air inlet of the 
cyclone dust collector, an air outlet of the 
cyclone dust collector is communicated with an inlet of the bath 
tower, an outlet of the bath tower, an inlet of the alkaline tower, an outlet of the alkaline tower and an inlet of the 
biological filter are sequentially communicated, an air outlet of the 
biological filter is connected with the induced draft fan, the bottom of the alkaline tower and the bottom of the biological filter are directly communicated with the top of the alkaline tower and the top of the biological filter respectively and communicated with a 
sewage disposal 
system used for carrying out 
secondary treatment on waste liquid produced by the alkaline tower and the biological filter. External water in a water replacement 
system in a 
sewage plant serves as absorbing solvents, the waste liquid 
coming out from the bottoms of the towers is treated through the 
sewage disposal 
system and then is returned to an absorbing tower, the use amount of water is greatly reduced, and operating expenses are reduced.