Objective To examine the effect and mechanism of bilobalide on cardiomyocytes hypoxia/reoxygenation injury. Methods The cells were divided into control group, hypoxia/reoxygenation group and bilobalide group. Cells in the control group were cultured in conventional incubator, and cells in the hypoxia/reoxygenation group were cultured in hypoxia incubator and conventional incubator alternatively. Cells in the bilobalide group were treated with 20 μmol/L bilobalide after incubation in the hypoxia/reoxygenation. The cell activity and content of oxidative stress and inflammatory response indicators were examined by related test kits. The flow cytometry and polynucleotide chain break detection technology were used to detect cell apoptosis. Western blotting was used to detect the levels of apoptosis related proteins and calcium channel protein. Immunofluorescence technology was used to detect intracellular calcium concentration. Results Compared with the control group, the hypoxia/reoxygenation group showed a decrease in cell activity and an increase in oxidative stress, inflammatory damage, cell apoptosis, calcium channel protein Cav1.2 level and intracellular calcium concentration (P＜0.05). Compared with the hypoxia/reoxygenation group, the bilobalide group showed an increase in the cell activity and decrease in oxidative stress, inflammatory damage, cell apoptosis, calcium channel protein Cav1.2 level and intracellular calcium concentration (P＜0.05). Conclusion Bilobalide may reduce cell apoptosis by reducing calcium channel protein Cav1.2 level and intracellular calcium concentration, thereby exerting a protective effect on rat cardiomyocytes H9C2 hypoxia/reoxygenation injury