The invention relates to a CrN/AlPO4 efficient thin-film flexible reflecting mirror with excellent durability. The thin-film flexible reflecting mirror comprises a flexible substrate and a functional thin-film stack layer deposited at the surface of the flexible substrate, wherein the functional thin-film stack layer comprises an optical reflecting film layer, a transparent transition layer and a high-reflectivity protection film layer. The efficient thin-film flexible reflecting mirror is not only light in weight and flexible, but also high in reflectivity, good in surface durability and weather resistance, and long in service life. Compared with an existing glass plane concentrating reflecting mirror, the thin-film flexible reflecting mirror has great competitive advantages.