Objectives We aimed to determine the prevalence of urinary incontinence (UI) during the peri‐ and postpartum period in women from Nanjing, China, and estimate its risk factors. Methods From January to December 2018, a total of 6500 postpartum women were enrolled and asked to complete the questionnaires. Of these, 6370 (98%) women returned the questionnaires with valid responses. Additional data were collected, including age, height, weight, gestation time and parity, and neonatal weight. The International Consultation on Incontinence Questionnaire‐Urinary Incontinence Short Form was used. Surface electromyography (sEMG) and a biofeedback training system were used as a testing platform, and PESEMG values were obtained. Results The prevalence of UI during pregnancy and at 6 weeks postpartum in women was 29.76% and 12.50%, respectively. The prevalence of stress UI (SUI), urge UI (UUI), mixed UI (MUI), and other types of UI that developed during pregnancy was 25.48%, 1.66%, 1.65%, and 0.97%, respectively. The prevalence of SUI, UUI, MUI, and other types of UI at 6 weeks postpartum was 8.49%, 2.07%, 1.16%, and 0.77%, respectively. Multivariate analysis showed that advanced age, greater postpartum body mass index (BMI), macrosomia, multiparity, and vaginal delivery were risk factors of postpartum UI. Women with mild degree of UI in pregnancy, those who had undergone cesarean section, and those without UI before pregnancy were relieved from UI at 6 weeks postpartum. Conclusions The rate of UI in peri‐ and postpartum women from Nanjing is consistent across China. The most common type of UI was SUI, with many risk factors affecting its occurrence. Advanced age, greater postpartum BMI, multiparity, macrosomia, and vaginal delivery might be the main risk factors of UI in postpartum women.