This paper studies the microscopic mechanisms of H₂ adsorption on the rutile TiO₂ (110) surface by the first-principle plane-wave ultrasoft pseudopotential method based on density functional theory. The changes in the adsorption energy, density of states, distribution of charges, and optical properties on the TiO₂ surface are calculated. The experimental results indicate that the rutile TiO₂ (110) surfaces doped with C, Mo, and C-Mo separately can easily adsorb H₂ in the way of chemical adsorption. After doping, the impurity level formed in the forbidden band can induce the separation of photogenerated electrons and holes. This provides a "step" for electron transitions in the forbidden band and improves the optical properties of the TiO₂ surface. In the visible light range of 380-780 nm, the optical performance of C-Mo co-doping,Mo doping, and C doping materials decreases in turn. The absorption coefficient and reflectance peak of the TiO₂ surface doped with C-Mo are increased by about 5 times and 6 times, respectively, compared with those of the undoped one. This study deepens the understanding of the microscopic mechanism of H₂ adsorption on the TiO₂ surface and improves the optical properties of the material by using the doping method, which provides theoretical support for the application of TiO₂ in hydrogen sensors.