The invention discloses a method of eliminating surface wrinkles of a degradable macromolecular film by ultraviolet irradiation. The method mainly comprises the following steps: with polydimethylsiloxane (PDMS) elastomer as a substrate, spin-coating a soft-hard composite system formed by an organic solvent solution with degradable macromolecules in certain percentage by mass, and applying an external stress to generate a wrinkle shape on the surface of the solution; and then, initializing disturbance and slackness of a stress field in a film/base composite system by means of a light degradation reaction of the macromolecular film so as to eliminate the surface wrinkles. By performing ultraviolet irradiation on the existing surface wrinkles, whether the surface wrinkles of the composite system are eliminated or not can be regulated by changing experimental parameters such as lighting dosage and controlling the relative size of the lighting dosage and interfacial residual stress. The method is simple to operate, is clean and efficient, and has a wide application prospect in preventing a material from losing efficacy and prolonging the service life of the material in the field of composite material.