A UV (ultraviolet) curing apparatus for a contact-lens polymerization process is provided. A UV curing module is equipped for the mold cavities of contact-lens curing molds, including a plurality of first UV light sources arranged above the mold cavities and a plurality of second UV light sources arranged below the mold cavities. A plurality of light output areas of a first light guide device guides the light beams emitted by the first UV light sources to illuminate upper light receiving surfaces of the molds. A plurality of reflecting plates of a second light guide device reflects and scatters the light beams emitted by the second UV light sources to lower light receiving surfaces of the molds. Thereby, the contact-lens polymer inside the molds is uniformly cured, and the yield is raised.