Gaohe Mine W1309 working face returning air along gob side entry and return air roadway distance was long, with large ventilation resistance, causing gas overrun in working face, affected production. The transformation of working face ventilation system turned double "U" ventilation form into "three feeding and one return" partial "Y" ventilation form, wind discharge capacity decreased obviously, the decrease of air distribution quantity effectively reduced gas emission in goaf, which provided effective guarantee for the improvement of working face average daily output.