Ischemia-reperfusion (I/R) injury is a significant clinical problem impacting the heart and other organs, such as the kidneys and liver. This study explores the protective effects of oxycodone on myocardial I/R injury and its underlying mechanisms. Using a myocardial I/R model in Sprague-Dawley (SD) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in H9c2 cells, we administered oxycodone and inhibited AMP-activated protein kinase (AMPK) with Compound C (C.C). Our results showed that oxycodone significantly reduced lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) production while stabilizing mitochondrial membrane potential (MMP). Western blot and RT-qPCR analyzes confirmed that oxycodone enhances AMPK phosphorylation and upregulates the expression of Silent Information Regulator 1 (SIRT1) and Peroxisome Proliferator-Activated Receptor γ Coactivator 1α (PGC-1α), thereby protecting myocardial cells. These findings suggest that oxycodone exerts significant protective effects against I/R injury by activating the AMPK pathway, offering new potential therapeutic targets for myocardial protection.