Progressive additional lenses have emerged with their unique advantages, and are widely used by people. In order to detect it quickly and accurately, a progressive additional lens diopter detection method with low cost, simple device and easy operation is proposed. This method is based on the transmission fringe deflection method, and the distribution of diopter of the whole lens can be quickly obtained by calculating the deflection of light angle caused by the lens. The advantages and disadvantages of diopter detection methods are summarized. Firstly, the principle of transmission fringe deflection method is analyzed and studied. Secondly, the experimental device based on transmission fringe deflection method is constructed, and the camera calibration and phase calculation technology in the system are introduced. Finally, the diopter detection experiment of progressive additional lens is carried out, the results are analyzed and compared with VM-2000. The results show that this method can effectively and quickly detect the diopter distribution of progressive additional lenses, and can also be extended to other lenses.