Objective: To investigate the mechanisms of dezocine on regulating H9C2 oxidative stress and apoptosis of rat cardiac myocytes induced by hypoxia-reoxygenation(H/R) by regulating the expressions of microRNA-7a- 5p(miR-7a-5p)/ubiquitin E3 ligase tripartite motif 10(TRIM10). Methods: H9C2 cells were divided into control group (cultured normally), H/R group (treated with hypoxia for 3 h and then reoxygenation for 4 h), different doses of dezocine intervention group (H9c2 cells were pretreated with dezocine at the concentrations of 10-7, 10-6 and 10-5 mmol/L for 24 h, and then treated with H/R), H/R+miR-7a-5p group (H9C2 cells were transfected with miR-7a-5p mimics and then treated with H/R), H/R+miR-NC group (H9C2 cells were transfected with miR-NC and then treated with H/R), H/R+Dezocine+anti-miR-7a-5p group (H9c2 cells transfected with anti-miR-7a-5p were pretreated with 10-5 mmol/L dezocine for 24 h, and then treated with H/R), H/R+dezocine+ anti-miR-NC Group (H9c2 cells transfected with anti-miR-NC were pretreated with 10-5 mmol/L dezocine for 24 h, and then treated with H/R). Each group of cells was set with 3 replicate wells, and the experiment was repeated 3 times. The content of malondialdehyde(MDA) and activity of superoxide dismutase(SOD) and glutathione peroxidas(GSH-Px) were detected by the enzyme-linked immunosorbent assay. The cells apoptosis was detected by flow cytometry. The protein expressions of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax) and TRIM10 were detected by Western blot, and the expressions of miR-7a-5p and TRIM10 mRNA were detected by real-time quantitative PCR(RT-qPCR). The double luciferase reporter gene experiment was used to verify the regulatory relationship between miR-7a-5p and TRIM10. Results: Compared with the control group, the MDA content, apoptosis rate, the expression of Bax protein, and the expression of TRIM10 mRNA and protein in the H/R group were all increased (P<0.05), while the activities of SOD and GSH-Px, and the expressions of Bcl-2 protein and miR-7a-5p were all decreased (P<0.05). Compared with the H/R group, the MDA content, apoptosis rate, the expression of Bax protein, and the expression of TRIM10 mRNA and protein in the different doses of dezocine intervention group were decreased (P<0.05), while the activities of SOD and GSH-Px, and the expressions of Bcl-2 protein and miR-7a-5p were all increased (P<0.05), and there were significant differences in each index between the different doses of dezocine intervention groups (P< 0.05). Compared with the H/R+miR-NC group, the MDA content, apoptosis rate, the protein expressions of Bax and TRIM10 in the H/R+miR-7a-5p group were decreased (P<0.05), while the activities of SOD and GSH-Px, and the expression of Bcl-2 protein were all increased (P<0.05). Compared with the H/R+dezocine+anti- miR-NC group, the MDA content, apoptosis rate, the protein expressions of Bax and TRIM10 in the H/R+dezocine+anti-miR-7a-5p group were all increased (P<0.05), while the activities of SOD and GSH-Px, and the expression of Bcl-2 protein were all decreased (P<0.05). Conclusion: Dezocine can reduce oxidative stress and apoptosis of rat cardiomyocytes H9C2 induced by H/R, which may play a role in regulating the miR-7a-5p / TRIM10 axis.