Objective: To analyze the effectiveness of musculoskeletal ultrasound in diagnosing rotator cuff injuries. Methods: A total of 80 patients with suspected rotator cuff injuries who were admitted and diagnosed between January 1, 2020, and December 31, 2024, were selected. Musculoskeletal ultrasound was performed on these patients, and the diagnostic efficacy of musculoskeletal ultrasound was evaluated by comparing the results with those of MRI. Results: The detection rates of musculoskeletal ultrasound for the location and extent of injury were similar to those of MRI (p > 0.05). Based on the MRI diagnosis results, the diagnostic accuracy rate of musculoskeletal ultrasound was 92.50%, with a sensitivity of 93.06% and a specificity of 87.50%. The morphological and signal characteristics, as well as ultrasound indicators, of patients with positive musculoskeletal ultrasound results differed significantly from those of patients with negative results (p < 0.05). Conclusion: Musculoskeletal ultrasound can effectively detect the location and extent of rotator cuff injuries, comprehensively assess the damage, and demonstrate high diagnostic efficacy. Furthermore, the morphological and signal characteristics, as well as ultrasound indicators, of musculoskeletal ultrasound can serve as diagnostic criteria for rotator cuff injuries, improving disease detection efficiency.