Abstract: The modulation transfer function (MTF) is currently recognized as the most objective and effective method for optical lens testing. In response to the issues of errors in ISO12233 edge detection data and poor noise resistance, a systematic optimization algorithm process was proposed. The accuracy of edge detection and noise suppression capabilities were enhanced by employing a Canny operator based on the Otsu method, the edge fitting error was reduced by substituting the Bisquare method for the least square method, and the data oscillation caused by noise and the errors in subsequent processing of discrete data were solved by using a cubic Fermi function to solve the edge spread function (ESF). Experimental results show that, compared with the ISO12233 algorithm, the optimized algorithm is more accurate, with test precision meeting standards, which is fully satisfied the requirements of lens testing tasks in actual industrial production.