Based on the analysis of the generating mechanism of nonuniformity noise in the infrared image, the principle of nonuniformity correction for infrared imaging system was presented. The correction method using digital image processing technique was discussed. A factor weighted correction circuit architecture and its hardware implementation were presented.By adopting the technique in the infrared imaging system, the nonuniform interference of the infrared image was suppressed effectively, and the visual quality of the infrared image improved greatly.