In this paper, the DFT method is employed to analyze the sensing and adsorption performance intrinsic MoTe 2 and Pt doped MoTe 2 to the characteristic oil dissolved gases (C 2 H 2 , C 2 H 4 , CO, and H 2 ). The value of binding energy demonstrates Pt atom prefer to be trapped at T Mo site among T H , T Mo , T Te , and T Br sites. Pt–MoTe 2 depicts the excellent adsorption property to the four gases compared with MoTe 2 . Based on the change of band gap, the conductivity and sensitivity of Pt–MoTe 2 decreases and increases after adsorption of four gases. The moderate recovery time reveals the higher gas-sensing and response of Pt–MoTe 2 to C 2 H 2 and C 2 H 4 than to CO and H 2 . This paper provides theoretical guidance of potential application of a novel and high-performance gas sensor for online-monitoring the characteristic dissolved gases in transformer.