Abstract: OBJECTIVE To understand the related factors of incision infection in postpartum women after cesarean section, and analyze the preventive effect of flushing with metronidazole on incision infection. METHODS A total of 1860 maternal women who underwent cesarean section in hospital from Jan. 2013 to Apr. 2015 were selected as the study subjects. The 156 cases of patients with postoperative incision infection were divided into infection group 1 and infection group 2 according to treatment methods, with 78 cases in each group. The uterine cavity, abdominal cavity and maternal abdominal incision of infection group 1 were immediately flushed with 0.5% metronidazole solution, and the infection group 2 was flushed with 0.9% normal saline. The incision infection rate and the first-phase healing rate of the incisions were observed in both groups, and the related factors of postoperative infection were analyzed. RESULTS A total of 156 women who underwent caesarean section had postoperative incision infection with the infection rate of 8.39%. There were 189 strains of pathogenic bacteria isolated from the cohort, of which 113 strains were gram-negative bacteria, accounting for 59.79%, mainly Escherichia coli, 76 strains were gram-positive bacteria, accounting for 40.21%, mainly Enterococcus. The body mass index, premature rupture of membranes, amniotic fluid contamination, associated underlying diseases, related invasive procedures, and intraoperative blood loss were related factors associated with incision infection after cesarean section (P<0.05). The healing rate of infection group 1 was 93.59% (73/78), which was significantly higher than 83.33% of infection group 2 (65/78)(P＜0.001). CONCLUSION Strict aseptic technique, active treatment of related underlying diseases, control of operative time and intraoperative blood loss, and maternal cesarean section washing with metronidazole solution are effective in reducing postoperative infection rate and improving maternal incision healing.