Background. Adult mid-clavicle fractures are common but there is no consensus on the optimal treatment. Objective. The present network meta-analysis investigated the safety and efficacy of plate internal fixation, intramedullary fixation, and conservative treatment for adult mid-clavicle fracture. Methods. PubMed, OVID, EMbase, Cochrane Library, VIP, WanFang, and CNKI databases were searched up to March 2020 by two independent researchers for randomized controlled trials (RCTs) including patients treated by plate fixation, intramedullary fixation, or conservative treatment for mid-clavicle fractures. Primary outcomes were Constant score, Disabilities of the Arm, Shoulder and Hand (DASH) score, nonunion rate, and healing time.  Data were analyzed using GeMTC 14.3 and Stata 14 software. Results. A total of 27 RCTs were included. The network meta-analysis revealed no significant differences in Constant score among groups at 3-months and 12-months post-treatment (P > 0.05); however, at 24-months, intramedullary and plate fixation treatments were superior to conservative treatment according to probability ranking. There were significant differences in DASH score at 3-, 12-, and 24-months post-treatment (P< 0.05), and again probability ranking indicated that intramedullary and plate fixation treatments were superior to conservative treatment at 3 and 12 months, while conservative treatment was superior at 24 months. Nonunion rate also differed among treatments, with intramedullary and plate fixation superior to conservative treatment by probability ranking. Finally, healing time was significantly shorter following intramedullary and plate fixation compared to conservative treatment. Conclusion. Plate internal fixation and intramedullary fixation achieve superior functional outcome, lower nonunion rate, and shorter healing time for treatment of adult mid-clavicle fractures compared to conservative treatment.