Abstract: In order to improve the performance of infrared target detection， firefly optimal deviation （FOD） algorithm was proposed. First， infrared target detection model was established， and structure of infrared image target gray value of optimal bias was estimated. Second， firefly update was adopted in region decided range. Third， infrared point target imaging of Airy spot energy distribution was considered firefly fitness function in optimization， and the algorithm flow was given. Finally， simulation showed that FOD algorithm could detect the target region in infrared image with accurate edge location and higher detection efficiency.

Key words: firefly, optimal deviation, infrared target, detection, gray value