In this study, the theoretical relationship between knee joint injury and muscle strength training is explored, and the biomechanical changes caused by injury, the role of muscle on joint stability, and the physiological basis of training are clarified. The implementation strategies of personalized training programs based on injury type and stage, scientific training intensity control, and coordinated use of diversified training types are explained. Multi-dimensional evaluation is conducted from the aspects of joint function recovery, muscle strength and morphological recovery, and improvement of knee joint biomechanical properties, providing theoretical and practical references for muscle strength training in knee joint injury rehabilitation.