In the present invention, a multi-film structure being coated on the surface of a workpiece is disclosed. The multi-film structure is formed by making a high-entropy material film of at least two layers and a non-high-entropy material film of at least one layer be stacked on each other. In addition, the multi-film structure can also be formed by making a first high-entropy material film of at least one layer and a second non-high-entropy material film of at least one layer be stacked on each other. This multi-film structure particularly contains interlaminar interfaces to inhibit crack extension and reduce plastic deformation, so that the hardness and toughness of the workpiece coated with this inventive multi-film structure would be obviously enhanced. Moreover, the appearance color of the workpiece can also be changed by the multi-film structure, wherein the color type is dependent on the optical interferences occurring in the multi-film structure.