Abstract: The actual distribution of film thickness of a 2.2 meter coating plant has been studied. The uniformity of film thickness has been adjusted by correction mask in experiments. Utilizing correction mask, preferable uniformity values of optical components using planet jigs and revolution jigs have been acquired respectively by experiment and the results for large aperture optical components are satisfactory. Uniformity value has been controlled within 0.7% for concave mirrors within 700 millimeter aperture. For plane surface mirror with the same aperture, the value was within 1%. And for the aperture beyond one meter, the uniformity value of optical components has been controlled within 1%. By this means, the reflecting mirrors and antireflection mirrors have been coated for astronomical obse