The traditional data-driven prediction modeling theory lacks sufficient support, resulting in problems such as low confidence accuracy of traditional modeling methods and insufficient engineering level of prediction algorithms in the prediction modeling of infrared guidance head equipment. The fault prediction technology based on data-driven and model fusion provides an important technical approach to solve these problems. This study established a digital twin framework for the performance degradation prediction of the optical-electrical detection system of infrared guidance head equipment. According to the working mechanism of the physical entity, it abstracts it into a physical model in the energy domain. Combining the physical model with historical detection data, simulation analysis is conducted to obtain the initial performance degradation model of the system. The Temporal Bayesian network diagram (TBN) evolution model for performance degradation is established using real-time monitoring data to achieve synchronous evolution with the physical entity. The state estimation and remaining useful life prediction of the physical entity are realized using the unscented Kalman filter (UKF) algorithm and verified through simulation. It overcomes the shortcomings of narrow adaptability of single data-driven and model-based prediction modeling methods and improves the accuracy by 100 times compared to the data-driven method, providing a technical foundation for the research on prediction and evaluation of infrared guidance head equipment.