In the tritium proliferation site of the fusion reactor, the tritium barrier coating can effectively prevent the diffusion of tritium into the cladding structure and avoid the degradation of the material and the loss of tritium resources. However, the performance of existing coatings (such as α-Al₂O₃ and Er₂O₃) in extreme environments such as irradiation is challenged, and high-entropy alloy coatings are considered to be an effective solution. In meeting the aforementioned requirements, (AlCrTaTiZr)N _x coatings were prepared on a Si substrate by magnetron sputtering under different N₂ flows. The crystal structure, microstructure, and elemental content of the coatings were studied by XRD, SEM, and EDS. When no N₂ was introduced, the film was amorphous. By contrast, when N₂ was introduced, the film developed a fcc structure, which was closely combined with the Si substrate, and the coating had good compactness. When the volume flow ratio of N₂ / (Ar + N₂) (R_N) is 15%, the crystallinity of the film was strongest. On the basis of the first principles method combined with the special quasi-random structure, an adsorption model of H₂ molecules on the (001) surface of (AlCrTaTiZr)N was constructed. The hydrogen isotope surface interaction of coatings under service conditions was constructed and studied on the basis of the experiments. First, the adsorption energy of different sites and adsorption modes, as well as the effect of stable adsorption on the mechanical properties of the coating under different H₂ coverages was calculated. Results indicate that the vertical adsorption Hollow sites are stable adsorption sites, and H₂ adsorption on the coating surface is dependent on physical adsorption. H₂ is adsorbed on the Hollow sites composed of CrTaTiZr. After adsorption, the volume modulus (B), shear modulus (G), Young's modulus (E), Poisson's ratio (\nu) and B / G of the coating decreased. From a macroscopic perspective, H₂ adsorption decreases the strength, hardness, and ductility of the coating.