Objective To understand the changing trend of incidence of surgical site infection (SSI) following oral and maxillofacial surgery, and explore the influence of American Society of Anesthesiologists(ASA) score, type of incision, duration of operation and surgical risk index. Methods Data of patients who were hospitalized and underwent oral and maxillofacial surgery in a tertiary dental hospital from 2007 to 2017 were retrospectively analyzed. Trend Chi-square test was used to analyze the changing trend of incidence of SSI, binary logistic regression was used to analyze the risk of SSI. Results From 2007 to 2017, incidence of SSI in patients with oral and maxillofacial surgery was 0.33%-0.93%, with an average of 0.71%; patients with high indexes of ASA score, type of incision, duration of operation and surgical risk had higher incidence and risk of SSI; incidence of SSI was the lowest in 2009. In patients with ASA score of P1, surgical risk index of grade 1, incidence of SSI declined from 0.72% and 2.79% in 2011 to 0.42% and 1.54% in 2017 respectively, with a decrease of more than 41%. Conclusion Incidence of SSI following oral and maxillofacial surgery decreased and finally remained at a low level during 11 years, with the increase of ASA score, risk indexes score of surgical incision type, duration of surgery and surgical risk, incidence and risk of SSI increased gradually, medical environment may be one of the factors that affected SSI.