Objective:To systematically review the correlation between caesarean section and delayed onset of lactogenesisⅡ (DOLⅡ) .Methods:We searched PubMed, Web of Science, China Biomedical Medline Disc, China National Knowledge Infrastructure, WanFang Data, and VIP through computers. The search period was from the establishment of the database to March 31, 2022. After two evaluators independently selected literature, extracted data, and evaluated the quality of the included studies, Meta-analysis was conducted using R 4.1.0 statistical software.Results:A total of 25 studies were included, involving 36 233 caesarean section women. Meta-analysis showed that the risk of DOLⅡ in caesarean section group was 1.74 times higher than that in natural childbirth group [ OR=1.74, 95% CI (1.46, 2.08), P<0.01]. Conclusions:Current evidence shows that caesarean section can increase the risk of DOLⅡ in delivery women. Due to the limitation of the number and quality of included studies, future studies need to further confirm the causality between caesarean section and DOL Ⅱ.