Cardiomyopathy comprises heterogeneous diseases characterized by structural or functional myocardial abnormalities and caused by conditions such as hypertension and coronary atherosclerotic heart disease. Current management relies mainly on pharmacotherapy and lifestyle interventions, but these approaches are limited by poor bioavailability and adverse effects. Nanoparticles (NPs) can deliver therapeutic drugs to cardiac muscle tissue through passive or active targeting, protecting the drugs they carry from premature degradation. They also show good biocompatibility and minimize damage to healthy tissues. This review summarizes the applications of NPs in cardiomyopathy and their active and passive targeting strategies, and provides a brief overview based on the mechanisms reported in individual published studies. It aims to provide therapeutic strategies for clinical management of cardiomyopathy and a theoretical foundation for future translational research.