Objective. To investigate the role and mechanism of protein kinase N2 (PKN2) in hydrogen peroxide (H2O2)-induced injury of PC12 cells. Methods. PC12 cells were transfected with lentivirus to knock down or overexpress PKN2 and then were treated with 300 μM H2O2 to establish a cell model of oxidative stress injury. The cell viability of PC12 cells in each group was determined by the CCK-8 method. Biochemical assays were used to measure reactive oxygen species (ROS), malondialdehyde (MDA) levels, and superoxide dismutase (SOD) activity. Western blot was used to detect the protein expressions of PKN2, caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, p-mTOR, and mTOR in PC12 cells in each group. Results. H2O2 treatment could significantly reduce PC12 cell viability and promote cell apoptosis and oxidative stress. PKN2 overexpression inhibited H2O2-induced apoptosis and oxidation damage by increasing PC12 cell viability, SOD activity, and p-mTOR protein expression, reducing intracellular ROS and MDA levels, and cleaved-caspase-3 and cleaved-PARP protein expression. Conclusion. PKN2 overexpression can alleviate H2O2-induced oxidative stress injury and apoptosis in PC12 cells by activating the mTOR pathway.