The invention discloses a free-form surface lens used for double ring-shaped uniform illumination. The free-form surface lens comprises a front-surface flat surface, a back-surface free-form surface and a side-surface cylindrical surface, wherein the front-surface flat surface is connected with the back-surface free-form surface by the side-surface cylindrical surface; the front-surface flat surface is vertical to the propagation direction of a laser beam; the back-surface free-form surface is used for deflecting the laser beam and comprises a first free-form surface, a second free-form surface and a cylindrical surface; the first free-form surface is connected with the second free-form surface by the cylindrical surface; the free-form surface lens is rotationally symmetrical about a coordinate axis z of an optical axis; after the laser beam is deflected by the first free-form surface, the illumination area of the laser beam on a target plane corresponds to an inner ring of the doublering-shaped uniform illumination; and after the laser beam is deflected by the second free-form surface, the illumination area of the laser beam on the target plane corresponds to an outer ring of the double ring-shaped uniform illumination. The free-form surface lens used for the double ring-shaped uniform illumination has the advantages of compact and simple structure, good shaping effect and high energy utilization rate.