Abstract: As a new type of microporous filter membrane, nuclear pore membrane can be obtained with varying pore density and pore diameter by controlling irradiation and etching conditions. Accurate measurement of pore diameter and density is critical to ensuring the precision filtration performance of nuclear pore membrane. The pore diameters of nuclear pore membrane typically range from sub-micron scales(0.1~1 μm) to over ten microns and can be observed through imaging techniques such as scanning electron microscopy or optical microscopy. An automatic measurement of pore diameter of nuclear pore membrane based on machine visual algorithm is developed. The scanning images of electron microscope or optical microscope are processed by USM(Unsharping Mask) sharpening, corrosion expansion, Hough circle detection and concentric circle detection, which can detect cone holes and repeated holes, and obtain the inner and outer diameters of nuclear pore membrane and their statistical distribution. This method detects the pore parameters of nuclear pore membrane under the microscope with high accuracy, and the deviation from manual statistics is within 5%. Additionally, the algorithm's rapid processing time significantly enhances detection efficiency. In optical microscopy applications for nuclear pore membrane image analysis, the system demonstrates exceptional recognition accuracy for diverse complex and pore geometries. This capability supports the integration of optical microscopy into automated quality control workflows for nuclear pore membrane production, enabling end-to-end automated pore diameter statistics.