The interaction mechanism between CO, CO 2 , and NO gas molecules and Pt n -SnS 2 (n = 1−3) and Pt n -MoTe 2 (n = 1− 3) is analyzed based on density functional theory calculations. For Pt 2 -SnS 2 , the structure of Pt 2 -SnS 2 is deformed during CO 2 adsorption. For Pt 3 -SnS 2 , its structure is also significantly deformed when the gas is adsorbed. Pt 2 -SnS 2 is not suitable for the detection and adsorption of CO 2 gas, while Pt 3 -SnS 2 is not suitable for the detection and adsorption of these three gases. According to the density of states and molecular orbital analysis, the conductivity of the adsorption system of Pt-SnS 2 remains almost unchanged after the adsorption of CO, so Pt-SnS 2 is not suitable for the detection of CO gases. The adsorption of gases on intrinsic MoTe 2 is a weakly interacting physical adsorption. Doping with one to three Pt atoms all resulted in different degrees of enhancement of the adsorption capacity of the substrates for these three target gases. However, for Pt 2 -MoTe 2 and Pt 3 -MoTe 2 , the structure of these two materials undergoes significant deformation upon NO adsorption. In addition, the interaction between Pt 3 -MoTe 2 and CO 2 is weak, and the conductivity of this system is almost unaffected by CO 2 adsorption. In addition, all other constructions are suitable for the detection of the corresponding gases. This paper provides a theoretical basis for the development of gas sensors for the detection of automotive and industrial emission gases.