OBJECTIVE：To systematically e valuate the efficacy and safety of duloxetine in the improvement of pain symptoms of knee osteoarthritis （KOA），and to provide evidence-based reference for clinical treatment of KOA. METHODS ：Retrieved from PubMed，Embase，Medline，Cochrane Library ，CNKI，VIP and Wanfang database ，during the establishment of the database to Sept. 2019，RCTs about duloxetine （trial group ）vs. placebo （control group ）in the improvement of pain symptoms of KOA were collected. After data extraction and quality evaluation using Cochrane system evaluator ’s manual 5.1.0，Meta-analysis was performed by using Stata 14.0 software for WOMAC total score ，WOMAC pain score ，WOMAC stiffness score ，WOMAC function score and BPI-S score ，as well as the incidence of adverse reaction such as dry mouth ，somnolence and nausea. RESULTS：A total of 6 RCTs were included ，involving 2 059 patients. Meta-analysis results showed that WOMAC total score [MD＝－0.34，95％CI（－0.48，－0.20），P＜0.05]，WOMAC pain score [MD ＝－0.41，95％CI（－0.54，－0.29），P＜0.05]， WOMAC stiffness score [MD ＝－0.24，95％ CI（－0.37，－0.12），P＜0.05]，WOMAC function score [MD ＝－0.43，95％CI （－0.55，－0.31），P＜0.05]，BPI-S score [MD ＝－0.38，95％CI（－0.48，－0.28），P＜0.05] of trial group were significantly lower than those of control group ；the incidence of dry mouth [RR ＝3.55，95％CI（2.00，6.29），P＜0.05]，somnolence [RR ＝3.23， 95％CI（1.88，5.54），P＜0.05] and nausea [RR ＝6.95，95％CI（2.99，16.15），P＜0.05] in trial group were significantly higher than control group ，with significant difference. CONCLUSIONS ：Duloxetine can relieve the pain and improve knee function in patients with KOA ，but it is necessary to pay attention to its adverse reactions.