〔Abstract〕 Objective To explore the molecular regulation mechanism of Astragalus polysaccharide based on human cardiac microvascular endothelial cells. Methods The 4th and 5th generations of human cardiac microvascular endothelial cells cultured in vitro in Luoyang Dongfang Hospital from January 2019 to December 2020 were selected as the observation objects. The regulatory mechanism of Astragalus polysaccharide was observed and analyzed by staining, cell enzyme-linked immunosorbent assay (ELISA) and immunochemistry. Results Astragalus polysaccharide could affect the surface adhesion molecules of human cardiac microvascular endothelial cells, mainly the expression of intercellular adhesion molecule-1 (ICAM-1) was promoted, the difference was statistically significant (P < 0.05), and there was no significant effect on the expression of CD18 on lymphocyte surface (P > 0.05). Conclusion In the environment of human heart microvascular endothelial cells, astragalus polysaccharides can enhance the expression of cell surface adhesion molecules well, be beneficial to the recycling of lymphocytes, and promote the adhesion between lymphocytes and endothelial cells. It is an important manifestation of Astragalus Polysaccharides in immune enhancement.