To explore the effect of buccal acupuncture on patients with obstructive sleep apnea syndrome complicated with metabolic syndrome and their quality of life.Methods:Seventy-six patients with obstructive sleep apnea syndrome complicated with metabolic syndrome admitted to the Second Affiliated Hospital of Guangzhou University of Chinese Medicine from December 2020 to March 2021 were selected as the research objects.They were randomly divided into a control group and an observation group，with 38 cases in each group.Routine acupuncture was used in the control group with a guiding diet and exercise，and buccal acupuncture was used in the observation group on the basis of the control group.Both groups continued to intervene for 3 courses of treatment.The maximum metabolic equivalent(METmax)，maximum oxygen uptake(VO2max)，6-minute walking distance(6-MWT)，Pittsburgh sleep quality index(PSQI) score，and left ventricular ejection fraction(LVEF) of the two groups were compared before and after treatment.Results:After 1 month of treatment，the METmax and VO2max in the two groups were higher than those before treatment(P<0.05)，and the METmax and VO2max in the observation group were higher than those in the conventional group(P<0.05).After 2 months of treatment，the score of 6-MWT was significantly higher than that before treatment(P<0.05)，and the observation group was better than the control group(P<0.05).After 2 months of treatment，the PSQI score of the two groups was significantly decreased(P<0.05)，and the observation group was significantly lower than the control group(P<0.05).After 1 month of treatment，the LVEF of the two groups was higher than that before treatment(P<0.05)，and the observation group was higher than the control group(P<0.05).The incidence of complications in the observation group was lower than that in the conventional group(χ2=5.208，P=0.022).Conclusion:Buccal acupuncture improves cardiopulmonary function，quality of life，exercise endurance，and LVEF in patients with obstructive sleep apnea syndrome complicated with metabolic syndrome，and it is safe and reliable，which is worth popularizing.