Panax notoginseng-steamed chicken (PNSC) is a common medicinal diet in China. In this study, we conducted comprehensive analysis to determine the effect of PNSC on uterine involution in postpartum mice and human umbilical vein endothelial cells. The role of the PI3K/AKT/mTOR pathway in this process was explored. Results showed that PNSC promoted the recovery of endometrial hyperplasia and uterine index in postpartum mice. In vitro and in vivo experiments indicated that PNSC activated PI3K/AKT/mTOR signaling pathway, promoted the proliferation of human umbilical vein endothelial cells (HUVEC), up-regulated the expression of VEGF, and its binding to VEGFR2. Moreover, it increased the expression of PCNA, MMP9, and CyclinD1 in the nucleus. Moreover, it up-regulated the secretion of hormones, such as prolactin (PRL), progesterone (P), as well as the level of vascular endothelial growth factor (VEGF) in mice, and down-regulated the secretion of endothelin-1 hormones (ET-1), thereby promoting uterine involution. In conclusion, this study demonstrates that PNSC can regulate angiogenesis to promote uterine involution by activating the PI3K/AKT/mTOR pathway.