For a motorized infrared measurement system single-point non-uniformity correction results are poor and two-point non-uniformity correction is restricted by many factors, a new non-uniformity correction method is put forward based on radiation attenuation. The method uses different attenuator to produce Infrared Focal Plane Array (IRFPA) response to achieve the two-point correction and the segmented two-point correction. The segmented two-point correction by the establishment of the decay rate and the IRFPA gray response curve can calculate any radiation response, and then the two-point correction finishes in the segment without prior measurement calibration source radiation. The experimental results show that the method is superior to conventional correction methods, and improves the uniformity about 50% under low radiation background. At the same time, the new correction methods have many advantages, such as environmental adaptability and simple operation.