[Abstract] Objective To evaluate the clinical efficacy and prognosis of Y-shaped reconstruction of coracoclavicular ligament with improved tightrope system in the treatment of acromioclavicular joint dislocation. Methods from January 2015 to January 2018, 20 patients with acromioclavicular joint dislocation treated by Y-shaped reconstruction of coracoclavicular ligament with improved tightrope system were selected as tightrope group, and 20 patients with acromioclavicular joint dislocation treated by clavicular hook plate were selected as clavicular hook plate group. Results two groups of patients were successfully operated. There were no significant differences in incision length, intraoperative blood loss and hospital stay between tightrope group and clavicular hook plate group (P > 0.05). The operation time of tightrope group was slightly longer than that of clavicular hook plate group. The difference was statistically significant (P < 0.05). Compared with the clavicular hook plate group, the tightrope group was significantly better in terms of VAS score at 2 weeks, Karlsson efficacy grading standard at 3 months and constant Murley shoulder function score at 6 months (P < 0.05). At the last follow-up, the complications in the tightrope group were significantly less than those in the clavicular hook plate group (x2 = 33.231, P < 0.001), and the difference was statistically significant (P < 0.05). Conclusion Y-shaped reconstruction of coracoclavicular ligament with improved tightrope system for acromioclavicular joint dislocation of Rockwood type Ⅲ ~ Ⅴ has satisfactory effect, less complications and is safe and reliable, which is worthy of promotion.