The "GB/T 44293-2024 Measuring method for numerical aperture image of microscope objective" standard describes in detail the principle, equipment, environment and steps of measuring the numerical aperture of microscope objective, which is suitable for infinity-corrected microscope objectives with a nominal value of numerical aperture greater than 1.00. The method is based on the principle of Optical inspection total reflection, and the numerical aperture is determined by the measurement of Optical inspection images formed at the lower surface of the coverslip and the air interface, which are carried out by means of Light source, collimating lens group, spectroscopic prism and image Sensors. The standard also analyzes the uncertainty in the measurement process to ensure the accuracy and Reliability of the measurement results. In addition, the relevant specifications cited in the standard provide the necessary theoretical support and technical requirements for measurement to ensure the scientificity and standardization of the test.