OBJECTIVE：To systematically evaluate th e efficacy and safety of glucagon-like peptide 1 receptor agonists semaglutide in the treatment of type 2 diabetes mellitus （T2DM），and to provide evidence-based reference for clinical treatment of T2DM. METHODS ：Retrieved from PubMed ，Embase，the Cochrane library ，ClinicalTrials.gov，CBM，CNKI and VIP ， randomized controlled trials （RCT） about oral semaglutide 3 mg，7 mg and 14 mg （trial group ） versus placebo or other glucose-lowering drugs （control group ）in the treatment of T 2DM were selected during the inception to May 2020. After extracting data from clinical studies that met the inclusion criteria ，quality evaluation was carried out with Cochrane systematic evaluation manual 5.1.0，Meta-analysis was performed by using Rev Man 5.3 statistical software. RESULTS ：A total of 6 RCTs involving 5 334 patients were included. Results of Meta-analysis showed that compared with control group ，trial group could significantly decreased HbA 1c level { 26 weeks [MD＝－0.62，95％CI（－0.88，－0.36），P＜0.001]，52 weeks [MD＝－0.51，95％CI（－0.72， －0.29），P＜0.001]}，FPG level { 26 weeks [MD＝－0.89，95％ CI（－1.31，－0.48），P＜0.001]，52 weeks [MD＝－0.68，95％CI （－1.05，－0.31），P＜0.001]}；significantly increased the compliance rate of HbA 1c＜7％ {26 weeks [RR＝2.22，95％CI（1.68， 2.93），P＜0.001]，52 weeks [RR＝2.02，95％CI（1.51，2.70），P＜0.001]}；significantly decreased the self-measured plasma glucose ， body weight and diastolic blood pressure （DBP）after 26 and 52 weeks of treatment，self-measured postprandial glucose cstc2015zdcy-ztzx120005） after 26 weeks of treatment and systolic blood pressure （SBP） E-mail： after 52 weeks of treatment（P＜0.05）. Subgroup analysis of different doses showed that compared with control group ，3 mg subgroup could significantly decreased the body weight after 26 and 52 weeks of treatment and DBP a fter 52 weeks of treatment ；7 mg subgroup could significantly decreased the HbA 1c levels and body weight after 26 and 52 weeks of treatment ，the FPG levels and the self-measured plasma glucose after 26 weeks of treatment and the SBP after 52 weeks of treatment ，increased the compliance rate of HbA 1c＜7％ after 26 weeks of treatment. The 14 mg subgroup could significantly decreased the HbA 1c levels ，the FPG levels ，the self-measured plasma glucose levels ，the body weight and the SBP after 26 and 52 weeks of treatment ，and self-measured postprandial glucose after 26 weeks of treatment ，while increased the complication rate of HbA 1c＜7％ after 26 and 52 weeks of treatment （P＜0.05）. The incidence of hypoglycemia events in trial group [RR ＝0.84，95％CI（0.72，0.97），P＝0.02] was significantly lower than control group ，but the incidence of adverse events [RR ＝1.23，95％CI（1.09，1.40），P＝0.001] and gastrointestinal reaction [RR ＝1.99，95％CI（1.55，2.57），P＜0.001] were significantly higher than control group. There was no significant difference in the incidence of serious adverse events or infection between 2 groups（P＞0.05）. CONCLUSIONS ：Oral semaglutide can effectively decrease blood glucose level ，increase the compliance rate of HbA 1c＜7.0％，reduce the body weight and blood pressure level of T 2DM patients ，and the 14 mg subgroup has the best effect. When using somaluptide ， we should pay attention to the occurrence of adverse events ， especially gastrointestinal adverse events.