Axial positioning maintaining device of optical element

The invention provides an axial positioning maintaining device of an optical element, comprising a lens, an adjustable lens seat, an installing base and a plurality of flexible columns, wherein the lens is arranged on the adjustable lens seat; the adjustable lens seat and the installing base are respectively provided with a plurality of first connecting holes and a plurality of second connecting holes correspondingly; the flexible columns can connect the adjustable lens seat and the installing base together by the first connecting holes and the second connecting holes; each flexible column comprises a main body part, a thread cylindrical end at the upper end of the main body part, and the installing base arranged at the lower end of the main body part; the main body part is connected withthe thread cylindrical end at the upper end of the main body part and the installing base arranged at the lower end of the main body part by transition parts; each transition part comprises a first flexible part, a second flexible part and a cylindrical part arranged between the first flexible part and the second flexible part; and the planes of the first flexible part and the second flexible part are vertical mutually after extension. In the axial positioning maintaining device provided by the invention, the function of radial adjustment can be achieved under the condition of ensuring axial positioning maintenance.