Thermal load is one of the main reasons for the failure of infrared detection system, therefore, thermal-structure coupling analysis of a certain type of infrared imaging optical detection module under different temperature loads by means of ANSYS Workbench software was performed in this study. First, the response of the back intercept between the optical lens and the detector under different temperature loads was observed, and then, the theoretical imaging quality was calculated by the optical software ZEMAX on the basis of the back intercept. Finally, the theoretical calculation models were verified by the environment test. Simultaneously, the deformation rule of the optical detection module under different temperature loads was obtained, and it was found that the conductivity coefficient and thermal expansivity of the installation material of the detector affected the stability of the detection module. This research can provide guidance on the design, optimization, and reliability of infrared imaging optical detection modules.