Objective To investigate the application effect of extracorporeal shock wave therapy at shoulder trigger points combined with core muscle group exercise training in rotator cuff injury. Methods A total of 85 patients with rotator cuff injury were randomly divided into single group (n=42) or combined group (n=43). The single group received extracorporeal shock wave therapy at shoulder trigger points, while the combined group received extracorporeal shock wave therapy at shoulder trigger points combined with core muscle group exercise training. The clinical efficacy after treatment, as well as shoulder joint function, shoulder joint scores, shoulder joint range of motion, and shoulder joint pain severity before and after treatment were compared between the two groups. Results After treatment, the total effective rate of the combined group was higher than that of the single group (P<0.05). After treatment, the total score of the Constant⁃Murley Shoulder Score scale and its dimension scores of pain, activities of daily living, range of motion, and muscle strength in both groups were higher than those before treatment, and the above scores in the combined group were higher than those in the single group (P<0.05). The total score of the University of California at Los Angeles Shoulder Scale and its dimension scores of pain, function, shoulder flexion angle, shoulder flexion muscle strength, and satisfaction with treatment in both groups were higher than those before treatment, and the above scores in the combined group were higher than those in the single group (P<0.05). The angles of shoulder flexion, abduction, lateral internal rotation, and lateral external rotation in both groups were greater than those before treatment, and the above angles in the combined group were greater than those in the single group (P<0.05). The Visual Analogue Scale (VAS) scores of both groups decreased with the extension of treatment time, and after 6 weeks and 12 weeks of treatment, the VAS score of the combined group was lower than that of the single group (P<0.05). Conclusion Extracorporeal shock wave therapy at shoulder trigger points combined with core muscle group exercise training is effective in treating rotator cuff injury, which can reduce the degree of pain and improve shoulder joint function and range of motion, with superior effect to single extracorporeal shock wave therapy at shoulder trigger points.