Abstract: Objective To explore the preventive effect of root cause analysis on reducing complications in the nursing process of sleep apnea syndrome(SAS). Methods A retrospective analysis of 50 SAS patients who came to Huzhou central Hospital for treatment from March 2018 to March 2019 as the observation group, the 50 patients were all taken the new root cause analysis method introduced by our hospital, and then a retrospective analysis of 50 SAS patients who came to Huzhou central Hospital for treatment from January 2017 to January 2018 as the control group, to compare the effect of the two groups after care and the incidence of complications. Results The blood oxygen saturation, times of apnea, time of apnea and heart rhythm of the two groups were significantly improved after the treatment, and the difference was statistically significant(all P<0.05). After treatment, we found that the blood oxygen saturation and heart rhythm of the patients in the observation group were significantly better than those in the sleeping state(all P<0.05). After treatment, the incidence of complications in the control group was 26.0%(13/50), and in the observation group it was 6.0%(3/50). The incidence of nursing adverse events decreased from 2.5% to 0.5%, and the incidence of infection events decreased from 21.2% to 5.8%. Conclusion Taking root cause analysis is beneficial to promote the recovery of patients and effectively reduce the incidence of complications.