Objectives: To investigate the risk profile of preterm birth (PTB) in 2018 in China. Method: A prospective multicentre case–control study was conducted in 15 hospitals located in seven provinces throughout three geographical areas (the Eastern, South‐Central and North‐Western regions) in China. A total of 3147 preterm (<37+0 weeks) and 3147 term (37+0 to 41+6 weeks) live‐birth mothers were included. Designed questionnaires were used to investigate maternal and fetal information. We calculated multivariable logistic regression and population attributable risk (PAR). Results: Iatrogenic PTB accounted for 48.1% of preterm mothers. Multivariable analysis showed PTB was significantly associated with six categories of maternal and fetal factors, adverse life‐style and psychological conditions (adjusted odds ratio (aOR) 2.063, 95% confidence interval (CI) 1.601–2.657) had the highest PAR% (60.1%). High school and below education level (PAR% = 25.8%), living in town or village (PAR% = 24.4%), low pregnant weight gain (PAR% = 16.8%), hypertensive disorders in pregnancy (aOR: 5.010, 95% CI: 4.039–6.216, PAR% = 15.3%), placental abnormality (aOR: 4.242, 95% CI: 3.454–5.211, PAR% = 14.1%) and multiple pregnancy (aOR: 10.990, 95% CI: 7.743–15.599, PAR% = 11.8%) were significantly associated with PTB with high PAR% value. Conclusion: The main risk factors for PTB in China were placental abnormality, hypertensive disorders in pregnancy and multiple pregnancy. Adverse life‐style and psychological conditions and socio‐economic disadvantage had high public health significance. [ABSTRACT FROM AUTHOR]