Gas sensors can effectively detect toxic, harmful, flammable and explosive gases with concentrations below the human olfactory limit, and have great research significance in the fields of military defense, environmental safety, medical diagnosis and so on. Among them, resistance gas sensor is widely used because of its low cost and universal suitability for civil gas detection. Gas sensing material is the core of gas sensor, and it is very important to design and synthesize suitable gas sensing material for developing high performance gas sensor.Based on the brief introduction of gas sensor, resistive gas sensor, and several traditional gas sensing materials of resistive gas sensor, this review focuses on the SnS2 gas sensing materials, a class of n-type semiconductors. The structure, properties, research status and limitations of SnS2 gas sensing materials are summarized. Several important methods to improve the performance of SnS2 gas sensing materials and SnS2-based gas sensors are summarized, including vacancy engineering, thermal activation engineering, photoactivation engineering and heterojunction engineering. The research trend of SnS2-based gas sensors is prospected.