Objective To investigate the sub-health status of midwives and its influencing factors, to establishment of the norms of Sub-Health Measurement Scale for midwives, and to provide basis for formulation of intervention strategies aiming to improve midwives′ health level. Methods Totally, 842 midwives were selected from 46 midwifery medical institutions in Fujian province by stratified cluster random sampling method. Data were collected using the Sub-Health Measurement Scale Version 1.0, the Social Support Rating Scale, the Pittsburgh Sleep Quality Index and the Fatigue Scale-14. The cut-off norm of the Sub-Health Measurement Scale was established among midwives. Univariate analysis and the logistic regression were used to analyze the influencing factors of sub-health. Results The cut-off norm of sub-health status was 65; the prevalence rate of sub-health in midwives was 68.88%; the prevalence rate for physical, psychological and social sub-health was 66.51%, 69.36% and 67.81% respectively; binary logistic regression analysis showed that the frequency of irregular meals per week, the duration of each exercise, the types of adverse life events, hospital types, job satisfaction, social support and sleep quality were the influencing factors of the midwives′ sub-health status（P<0.01 for all）. Conclusion The sub-health status of midwives is a significant problem and affected by many factors. Managers and midwives themselves should improve awareness of health care and take measures to reverse midwives′ sub-health state, so as to improve the health level of midwives.