Abstract: Because of its safety and environmental protection, gas injection displacement has become one of the main methods to solve the problem of gas drainage in low-permeability coal seams in recent years. The mechanism of gas injection displacement was divided into gas displacement, driving and pore pressure. The role of influencing factors such as gas injection pressure, gas type and temperature was analyzed. It is concluded that the driving effect plays a leading role in gas injection displacement, which is mainly enhanced by pressure potential difference, and is different from other fracturing methods. The research progress of gas injection displacement technology is summarized, and the relevant key points and difficulties are summarized. It is considered that most of the experiments are based on univariate research, and there are few studies considering the joint action of composite influencing factors. Finally, based on the current application of gas injection displacement technology, the relevant technologies in the future is prospected from three aspects: gas injection displacement technology combined with fracturing measures, intelligent gas injection displacement technology and high-temperature gas injection displacement technology.