In order to explore the postoperative nursing effect and functional rehabilitation of rotator cuff repair under ultrasound diagnosis, a method of nursing and rehabilitation functional training for athletes' wrist injury under the assistance of microscopic B-ultrasound was proposed. This study retrospectively analyzed the therapeutic effect of tendon anastomosis in 237 patients with wrist tendon injury, adopted nursing measures such as health education and functional exercise, and observed its clinical effect. The results showed that after 3-6 months of follow-up, all patients had satisfactory recovery of tendon function. Of these, 132 patients recovered well. 84 patients recovered well. The excellent and good rate of patients was 91%. Ultrasound diagnosis of rotator cuff repair combined with functional exercise promotes good recovery of shoulder joint function in patients.