Abstract: In addressing the challenges posed by the intricate system requirements of infrared thermal imaging products, which are challenging to trace and verify, this paper puts forward a novel system design method. This approach is founded upon Model-Based System Engineering (MBSE) with the objective of enhancing the coherence of infrared thermal imaging products within the context of system design, model-driven development, and responsiveness to requirements. The research process commences with an examination of the present status of MBSE and its technical application effectiveness. This serves as a foundation to propose a digital development mode of MBSE for thermal imaging products. The subsequent analysis delves into the intricacies of system model design, system architecture construction, and logical validation process methods within this mode. Additionally, a comprehensive validation of the system design method is conducted by measuring the quantitative temperature on the inner surface of a building enclosure. This case study is presented as a practical demand use case. The paper then goes on to present a comprehensive verification of the system design method.