Background: Simulation as an extensive used method for obstetric education is usually practiced for beginners, here we offered a course with simulated practice of performing a mediolateral episiotomy (MLE) for obstetricians and midwives in different seniority, and to evaluate the training effect on their knowledge and accuracy of cutting a MLE before and after the course.Methods: 82 participants were recruited at three different obstetric centers, included 35 obstetricians and 47 midwives. More than 5 years obstetric work in their careers were deemed to senior ones, and there were 29 junior and 53 senior ones. A 30 minutes training course were given to all participants by one senior obstetrician. Special paper pads simulating perineum at crowning were used to cut MLE before and after the course, and a questionnaire about their occupation characteristics was given before the course. Three parameters of the MLE were analyzed and compared. Results: On performing MLE, midwives had more training history and conducted cases than obstetricians (p < 0.01). After the course, the mean values of three parameters were significantly increased from 31.46 mm in length, 48 degrees in angle and 9.09 mm in distance to 34.29 mm, 50.622 degrees and 10.82 mm respectively. In subgroups, obstetricians had angle degrees increased significantly (p =0.022), while midwives had the length and distance increased significantly (p=0.001, p=0.004). Senior participants had the length and distance of incisions increased significantly (P=0.008, P=0.020), the accuracy of these two parameters also improved significantly (P=0.002, P=0.034). In subgroups of midwives and seniors, the accuracy of the length and distance also improved significantly after the course.Conclusions: Obstetricians need more professional training about midwifery including episiotomy. Simulated training of this mode is suitable for obstetric education like performing MLE. The absence of senior obstetricians and midwives should be avoided in such medical education.