Abstract: Muscle fatigue induced by military training directly affects training effectiveness and injury risk, highlighting the urgent need for a scientifically validated assessment system. This review focuses on the mechanisms underlying muscle fatigue and summarizes subjective evaluation methods and objective detection techniques applicable to military training scenarios, along with an analysis of their respective advantages and limitations. The application status and development trends of modern monitoring technologies—such as wearable biosensors and ultrasound imaging—are also discussed. The analysis indicates that current muscle fatigue assessment in military training lacks a unified, multidimensional "gold standard." With advances in sensor technology, establishing a precise, real-time assessment system tailored to actual combat training requirements will facilitate optimized training implementation, reduce injury risks, and enhance overall training efficacy.