Oil-immersed power transformers generate characteristic gases after failure,Therefore, it is necessary to analyse and monitor the soluble gases in transformer oil samples. In this study, the DFT calculation method was used to study the adsorption properties of H-2, CO, C2H2, and C2H4 gases in oil on both intrinsic MoTe2 and Rh-doped MoTe2 films. In order to analyse the adsorption characteristics, this paper first obtains the most stable Rh-doped MoTe2 monolayer model through the modelling and computational analysis of different doping sites, then, the adsorption of these gases on the material surface is studied by analysing adsorption energy, charge transfer, total state density, parting density, energy band structure, differential charge density map, molecular front orbital and desorption time, and finally concludes that Rh-MoTe2 monolayer film is the ideal material for hydrogen sensing elements, due to the extremely long desorption time of CO gas, indicating that CO gas is hard to desorption on the surface of adsorbent,which shows that this process has played a certain role in promoting CO removal.