Abstract: A dynamic nonuniformity correction and radiometric calibration algorithm for infrared focal plane array was presented. Point to the problems of traditional radiation calibration and correction methods, a dynamic infrared calibration and correction technology using U-shaped blackbody was proposed which was a new conception. The temperature of the U-shaped blackbody was controllable, so dynamic infrared calibration could be done after nonuniformity correction so as to modify the drift of the original calibration table. The U-shaped blackbody diaphragm stretched out in high and low temperature respectively. After comparing that with the initial calibration data, the desired amended parameters were calculated to update the whole initial lookup table for radiometric correction. This algorithm could amend the drifts from initial radiometric calibration data, reduce the volume and weight of dynamic radiometric calibrator, and totally avoid the blocking of the FOV in traditional radiometric calibration. An U-shaped blackbody was designed and an experimental platform was built to evaluate the algorithm. It proves to get a satisfying correction effect after being tested by using real infrared images, and the error is less to 0.5 K after radiometric calibration modification.