Two-dimensional (2D) metal sulfide materials are ideal for use in gas sensing applications due to their low electronic noise and a large specific surface area, and the research on highly efficient and morphologically controllable methods for preparing two-dimensional metal sulfide materials is necessary. Highly crystalline 2D hexagonal SnS₂ nanoplates (NPs) with different morphologies were prepared by high temperature chemical bath method. SnS₂ NPs were characterized by different techniques, and their gas sensing properties were further investigated. The results show that when the molar ratio of oleic acid (OAc) to oleylamine (OAm) is 1 : 1, the shape of typical SnS₂ NPs is a uniform hexagon, with a diameter of about 150 nm and a thickness of 4-6 nm. The gas sensing test shows typical SnS₂ NPs are responsive to NO₂ gas, and the sensing process is reversible and selective. The optimal operating temperature is 130 ℃, and the response and recovery time are 98 and 680 s, respectively.