In order to meet the need of outfield thermal infrared imager performance test equipments in military, a set of the outfield of thermal infrared imager performance test system is designed. Based on several current typical test system product, through the equivalent band patterns method, the detection of thermal imaging system is predicted under various probability, the model of recognize the distance is distinguished, the detection and correction factors of various infrared equipments are determined, the accurate parameters in performance test are gotten, overall design scheme and implementation method is designed. Analysis the measured data show: the test system has certain creativity in structure design, which can meet the need of military equipments repair and guarantee and has application value.