The reliability requirements for detector assembly have increased significantly with the development of infrared detector technology. Traditional methods of assessing detector reliability along with the entire system are insufficient to meet these requirements. To address this issue, this paper investigates the reliability verification of a 640×512 (25 ?m) mid-wave infrared detector module under environmental stress. Key components of the detector were subjected to high-temperature accelerated life tests and continuous operation tests. The overall reliability of the detector module was estimated based on the specialized reliability test data of critical components. The evaluation results, using selected reliability assessment methods, indicate that the developed module meets the reliability standards. The reliability verification and assessment methods used in this study provide an objective and accurate evaluation of the cooled infrared detector module.