Abstract: Muscle architecture is a critical determinant of sports performance. As a non-invasive imaging technique, Musculoskeletal Ultrasonography (MSKUS) has become an effective method in assessing the relationship between muscle structure and performance because of its portability, operability, nonradioactive and cost-effectiveness. It is found that: 1) MSKUS can measure fascicle length, pennation angle, muscle cross-sectional area (CSA), and muscle thickness, these parameters directly affect muscle contraction mechanics, force transmission efficiency, and force generation capacity, thereby influencing physical attributes such as muscle strength and power. Specifically, fascicle length determines the range of muscle shortening, pennation angle influences force transmission efficiency, and muscle CSA and thickness are related to force generation capacity. 2) Different sports disciplines impose specific structural adaptations on muscles. Sprinters typically exhibit longer fascicle lengths and larger muscle CSAs to optimize their explosive power; distance runners tend to have greater pennation angles and smaller CSAs to meet endurance demands; strength athletes possess larger muscle CSAs and shorter fascicle lengths to enhance force generation and transmission efficiency. These muscle structural characteristics provide new perspectives and theoretical foundations for athlete selection and personalized training. 3) In the field of sports injury, regular monitoring of fascicle length and CSA changes can effectively assess muscle function status, so as to identify individuals at high risk of injury, and provide scientific evidence for post-injury rehabilitation and return-to-play decisions. 4) Based on the adaptive and plastic nature of muscles, resistance training, plyometric training, ballistic training, and stretching training promote diverse adaptations of muscle structure and function through their unique mechanisms, thereby to enhance muscle strength, increase explosiveness, and improve flexibility and agility. Given the significant applications of MSKUS in evaluating physical fitness, sport-specific performance, injury prevention, and rehabilitation, it is recommended to set MSKUS as an important tool for performance analysis and athlete potential assessment, and it could be included in current performance evaluation and training systems.