Abstract: At present, there are few applications of exhaust gas volume reduction technologies in iron and steel process, mainly being the sintering exhaust recycling technology. According to the characteristics of exhaust gas from iron and steel enterprises, such as waste gas components, last volume, temperature, oxygen content and heat value, two waste gas volume reduction technologies were put forward. One is to put the exhaust gas from raw material yard into lime kiln process to serve as the cooling air for vertical cooler, and the other is to transport the secondary high-temperature waste gas from converter to hot blast stove as combustion air. The waste gas volume reduction potential of the two kinds of technologies was analyzed respectively. The results showed that if the above technologies were widely applied in iron and steel industry, an annual reduction of 7.703×10¹¹ cubic meters of waste gas volume, an annual reduction of 1.54×10⁴ tonnes of dust emission, and a saving of 3.58×10⁶ tonnes of standard coal consumption can realized.