1. In the super-clean worktable, clean the lens. 2. Add photosensitive glue to concave surface, and then put convex lens on it, and ensure that there is no impurity in adhesive layer. 3. Use the center deviation measuring instrument to test and adjust the concentricity of the two lenses. After meeting the requirements, irradiate with purple light to solidify the photosensitive glue. 4. After the adhesive layer is cured, clean the lens.