Puguang gas purification plant, with an annual gas processing capacity of 120 x 108m³ and an annual purified gas output capacity of 93 x 108m³ is the first high sour gas purification plant with 100 x 108m³ processing capacity in China up to now. Natural gas consumption amount is very large due to its large processing capacity. In order to control and reduce gas consumption as far as possible, optimized are technological process and design parameters and analyzed are causes of large gas consumption. Taken are such measures as decreasing gas consumption during startup and shutdown, increasing flash steam recovery and utilization and lowering self-used gas of equipment, accordingly, gas consumption amount of the plant is greatly reduced. The study result can provide valuable reference for other high sour gas processing units.