In order to improve the uniformity of gas injection mixture and determine the reasonable structural parameters of the injection tube，Fluent numerical simulation software is used to model and simulate the flow field of the gas injection system，and analyze the effects of different injection speeds（30，40，50 m/s），injection hole angles（0°，30°，60°）and tube spacing（500，600，700 mm）on the peak volume fraction of gas at the sintered material surface and the injection range. The results show that: with double-hole injection，the peak volume fraction of gas at the sintered material surface and the injection range gradually increase as the speed increases；with the increase of the angle of the injection hole，the peak volume fraction of gas at the sintered material surface gradually decreases and the injection range gradually increases；with the increase of the tube spacing，the peak volume fraction of gas at the sintered material surface and the injection range first increase and then decrease；at 300~500 Nm³/h injection volume，the preferred injection hole angle is 60° and the tube spacing is 700 mm. After the new technology is successfully applied to the industrial site of Zhongtian Iron and Steel，the solid fuel consumption per ton of mine is reduced by 2.8 kg when the total injection flow rate is 300 Nm³/h.