The invention discloses an aluminum/aluminum oxide composite hydrogen resistance coating layer. The hydrogen resistance coating layer is a single-layer coating layer which is formed on a metal substrate and composed of xAl-(1-x)Al2O3, wherein x is larger than 0 and smaller than 1. The metal substrate is made of austenitic stainless steel or martensitic stainless steel. The hydrogen resistance coating layer is prepared through a physical vapor deposition method, a magnetron sputtering method is preferred, and the hydrogen resistance coating layer is obtained by conducting sputtering on an aluminum target and an aluminum oxide target at the same time. Combination between the aluminum/aluminum oxide composite hydrogen resistance coating layer and the metal substrate is combination between metal and metal, and the combination strength is high; compared with the coefficient of thermal expansion of a metal aluminum layer, the coefficient of thermal expansion of the hydrogen resistance coating layer is lower, thermal expansion mismatching between the hydrogen resistance coating layer and a surface aluminum oxide film is reduced, and the cold and heat impact preventing performance of the hydrogen resistance coating layer is improved; and under the condition that the surface aluminum oxide film is broken, a new aluminum oxide film can be generated in situ.