NO_x treatment is the key to tackle the key problem of sintering ultra-low emission. Reducing NO_x from the source is helpful to reduce the pressure of sintering end treatment and improve the treatment level. Blast furnace gas ash is usually returned to sintering process as solid waste,which has the characteristics of 0. 15%~0. 35% N content and particle size less than 0. 5 mm. Aiming at the source control of NO_x emission,a study is carried out on the influence of sintering with blast furnace gas ash on NO_x emission. The study shows that adding the blast furnace gas ash instead of about 0. 7%~1. 0% fuel in sintering can help to reduce the emission of NO by about 20 ~ 70 mg/Nm³;the extent of NO_x decline is affected by the N content and catalytic agent in gas ash, and the content of forming pellets (P) granules by the gas ash.