Objective to observe the effects of growth differentiation factor-15 (GDF-15) on collateral circulation and cardiac function in rats with acute myocardial infarction (AMI) by activating the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling pathway. Methods The AMI rat model was constructed by ligating the left anterior descending coronary artery. After successful modeling, the rats were randomly divided into sham operation group, model group, and GDF-15 group, with 12 rats in each group. The rats in the GDF-15 group were intraperitoneally injected with recombinant GDF-15 protein, and the other two groups were injected with the same amount of normal saline twice a week for 8 consecutive weeks. Echocardiography was used to detect the cardiac function of rats; HE staining was used to observe the pathological damage of rat myocardial tissue; CD31 immunohistochemical staining was used to observe the collateral circulation in rats; qPCR was used to detect the expression of vascular endothelial growth factor (VEGF) mRNA; kits were used to detect the expression levels of NO, reactive oxygen species (ROS), and cGMP; Western blot was used to detect the expressions of VEGF, eNOS monomer, pser1177eNOS monomer, eNOS dimer, and PKG protein. Results Compared with the sham operation group, the left ventricular end-systolic diameter (LVEDs), left ventricular end-diastolic diameter (LVEDd) increased, the left ventricular ejection fraction (LVEF), and the short-axis shortening rate (FS) decreased in the model group, the myocardial cell necrosis was severe, the vascular density in the infarcted area decreased, the VEGF mRNA level decreased, the levels of NO, eNOS dimer, cGMP, and the expression of PKG protein decreased, and the expression levels of ROS, eNOS monomer, and pser1177eNOS monomer increased (P < 0.05). Compared with the model group, the LVEDs and LVEDd decreased, the LVEF and FS increased, the myocardial cell necrosis was relieved, the vascular density in the infarcted area increased significantly, the VEGF mRNA level increased, the levels of VEGF, NO, eNOS dimer, cGMP, and the expression of PKG protein increased, and the expression levels of ROS, eNOS monomer, and pser1177eNOS monomer decreased in the GDF-15 group (P < 0.05). Conclusion GDF-15 can promote collateral circulation in ischemic myocardium and improve cardiac function by inhibiting eNOS decoupling and activating the NO-cGMP-PKG pathway.