Background Analysis of “maternal near-misses” is expected to facilitate assessment of the quality of maternity care in health facilities. Therefore, this study aimed to investigate incidence, risk factors and causes of maternal near-misses (MNM) admitted to the intensive care unit (ICU) within five years by using the World Health Organization’s MNM approach. Methods A five-year retrospective study was conducted in Subei People’s Hospital of Yangzhou, Jiangsu Province from January 1, 2015 to December 31, 2019. Risk factors in 65 women with MNM in the intensive care unit (ICU) were explored by using chi-square tests and multivariable logistic regression analysis. Causes and interventions in MNM were investigated by descriptive analysis. Results Average maternal near-miss incidence ratio (MNMIR) for ICU admission was 3.5 per 1000 live births. Average maternal mortality ratio (MMR) was 5 per 100,000 live births. MI for all MNM was 0.7%. Steady growth of MNMIR in ICU was witnessed in the five-year study period. Women who were referred from other hospitals (aOR 3.32; 95%CI 1.40–7.32) and had cesarean birth (aOR 4.96; 95%CI 1.66–14.86) were more likely to be admitted in ICU. Neonates born to women with MNM admitted in ICU had lower birthweight (aOR 5.41; 95%CI 2.53–11.58) and Apgar score at 5 min (aOR 6.39; 95%CI 2.20–18.55) compared with women with MNM outside ICU. ICU admission because of MNM occurred mostly postpartum (n = 63; 96.9%). Leading direct obstetric causes of MNM admitted in ICU were hypertensive diseases of pregnancy (n = 24; 36.9%), followed by postpartum hemorrhage (n = 14; 21.5%), while the leading indirect obstetric cause was heart diseases (n = 3; 4.6%). Conclusions Risk factors that were associated with MNM in ICU were referral and cesarean birth. Hypertensive disease of pregnancy and postpartum hemorrhage were the main obstetric causes of MNM in ICU. These findings would provide guidance to improve professional skills of primary health care providers and encourage vaginal birth in the absence of medical indications for cesarean birth.