Objective To explore the effects of constructivism learning theory-based，multiple net work platform-assisted breastfeeding education to primiparas. Methods Seventy-six primiparas were randomized into an experimental group of 36 and a control group of 40. The control group was given traditional breastfeeding education, while the experimental group additionally received constructivism learning theory-based，multiple net work platform-assisted breastfeeding education, in which the teaching contents were designed based on the constructivism learning theory including such five modules as breastfeeding lecture, questions and answers regarding breastfeeding knowledge, ′scaffolding′ breastfeeding skills demonstration, ′anchored′ breastfeeding case analysis, and random access to online communication. The education was provided through WeChat platform, ′rain class′ App and WeChat group chatting and interaction was organized. Breastfeeding knowledge, self-efficacy, 6-month exclusive breastfeeding rate and infants′ height and weight at the 6 months were compared between the two groups. Results The experimental group had higher breastfeeding knowledge and self-efficacy after 2 months of intervention and during postpartum hospitalization, as well as higher 6-month exclusive breastfeeding rate compared with the control group （P＜0.01 for all）. Conclusion Implementing constructivism learning theory-based,multiple network platform-assisted breastfeeding education to primiparas can effectively enhance their breastfeeding knowledge and beliefs, strengthen their breastfeeding behavior, thus to promote mothers′ and children′s health.