In the field of modern optical measurement, the center thickness is a basic parameter of the optical lens, which will directly, affects the accuracy of the lens’ focal length and other optical parameters, and these parameters have great influence on overall performance of the optical system. Therefore center thickness requires precision test. Nowadays, the methods include contact measurement and non-contact measurement. Generally speaking, the center thickness of the lens with no hole in the center only could be measured through the both methods. The lens with a hole in the center is used widely, on the basis of principle of contact measurement, a method of measuring center thickness of the lens with a hole is proposed. A sign convention about radius and sagitta of curvature is defined and the geometrical expressions are derived in detail. Analyses and simulations between the errors of center thickness and variables are shown. To prove the right of the method, an experiment is done in use of a lens with no hole in the center. The results of indirect and direct measurements are presented, respectively. In comparison of direct measurement, the proposed method has a high precision.