After years of research and development, the cooled mercury cadmium telluride (MCT) middle-wavelength infrared (MWIR) detectors have achieved mass production capacity, and the array specifications have also developed from the initial 320×256 to the current 1280×1024 megapixel level. At present, as the detector product level of Wuhan Guide Infrared Co., Ltd. (hereinafter referred to as "Guide Infrared company") is continuously improving, thermal imaging systems based on infrared detectors are widely used in airborne, shipborne, land combat, handheld observation and other military equipments. Taking the 640×512/15 μm MCT MWIR detector as an example, the engineering application of Guide Infrared company′s detector products is introduced, and the problems that need to be solved during the development of the detectors are analyzed. Finally, the future development and application direction of the detectors is pointed out.