[Objective] To analyze the causes of redislocation of acromioclavicular joint after arthroscopic suspension loop plate surgery. [Methods] 36 patients with acromioclavicular dislocation were treated with suspension loop plate under arthroscope. The cases of postoperative reduction loss were followed up and the specific reasons were analyzed. [Results] All patients were followed up for more than 6 months, among which 3 cases were redislocated after operation, the cause was osteoporosis in 1 case; Premature weight bearing in 1 case; Poor bone tunnel in 1 case; Constant-murley score was (90.04±2.90) and ASES score was (81.04±3.49) 6 months after surgery.[Conclusion] Acromioclavicular joint redislocation after surgery is a serious postoperative complication of shoulder arthroscopic suspension loop plate treatment for acromioclavicular joint dislocation. The reasons include osteoporosis, premature weight bearing, poor bone tunnel, etc., which is worthy of clinical attention.