Objective To investigate the effect and mechanism of Nardosinone (Nar) in hypoxia-induced apoptosis of H9c2 cardiomyocytes meditated through the PI3K/ Akt/ mTOR pathway. Methods Cobalt chloride (CoCl₂ ) was used to establish a hypoxic injury model in H9c2 cardiomyocytes. Cell proliferation was assessed by CCK-8 assays. Hoechst 33342 was applied to counterstain cells, and laser scanning confocal microscopy was used to observe apoptosis. The potential signaling pathway of Nar in treating IHD was predicted by network pharmacology. Western blot was used to detect expression of apoptosis-, autophagy-, and PI3K/ Akt/ mTOR pathway-related proteins. Results The PI3K/ Akt/mTOR pathway is major signaling pathway in Nar treatment of IHD. Compared with the control group, CoCl₂ (400 μmol/ L)decreased cell proliferation, the Bcl-2/ Bax ratio, PI3K, Akt and mTOR protein phosphorylation levels, and P62 protein expression, while increasing nuclear apoptotic fragmentation, the LC3II/ LC3I ratio, and Cleaved-Caspase-3 and Beclin-1 protein expression (P<0. 05). Compared with the CoCl₂ group, Nar (50 μmol/ L) pretreatment significantly increased cell proliferation, alleviated nuclear apoptotic fragmentation, decreased Cleaved-Caspase-3 protein expression, increased the Bcl-2/ Bax ratio, and increased PI3K, Akt and mTOR phosphorylation levels and P62 protein expression. The LC3II/ LC3I ratio and the Beclin-1 protein expression were also decreased (P< 0. 05). Pretreatment with PI3K specific inhibitor LY294002 offset the effects of Nar on CoCl₂-induced apoptosis, PI3K/ Akt/ mTOR pathway-related proteins, and P62 protein expression, but had no effect on the LC3II/ LC3I ratio or Beclin-1 expression. Conclusions Nar inhibited CoCl₂-induced H9c2 cardiomyocyte apoptosis by activating the PI3K/ Akt/ mTOR pathway, but probably alleviated the damage caused by excessive autophagy in cells through other pathways.