Abstract: Power electronic devices serve as the core components for electrical energy conversion and management in power electronics systems. During actual operation, complex working conditions and power fluctuations often lead to significant junction temperature variations. Prolonged thermal stress accelerates device aging, directly impairing system reliability. At present, this field still faces considerable challenges in accurate online junction temperature monitoring, device reliability modeling and lifetime prediction, as well as integrated thermal management and state-based control. Therefore, it has become an important technological evolution path to jointly enhance the accuracy of junction temperature sensing and the systematic approach to reliability management, thereby advancing power electronic modules toward higher levels of intelligence and autonomy. Relevant research primarily focuses on the current state of technology, key challenges, and future trends in junction temperature monitoring methods and reliability management strategies.