The combustion-supporting effect of steam to coke breeze in sintering has the potential to improve sinter quality and reduce pollutants emissions. The results show that increasing the by-product steam injection concentration(0.32-0.47vol%) and prolonging the injection time(5min) within a proper range(10-15min) can improve sinter quality. 2.13kgce/t−sinter of the fuel consumption was decreased by reducing coke breeze usage from 5.60–5.45% under the recommended parameters, with 15.16% decrease of CO in sintering waste gas. By comparing experimental data with thermodynamic calculations, although the reaction between CO and steam can reduce CO emission and generate H2, steam tends to react with coke breeze to generate H2 and CO(react at 674℃), and OH radical produced by H2 which can reduce the activation energy of CO oxidation reaction is the key to reducing pollutant emissions. The application of steam injection technology, excluding the equipment modification and steam injection cost of $300,000, can achieve a profit of $737491.2 per year. Therefore, low-carbon and cleaner iron ore sintering production can be realized through applying by-product steam.