Abstract: Soft electronics, as an innovative technology, enables the fabrication of organic/inorganic electronic devices on flexible or stretchable substrates, demonstrating tremendous potential in disease diagnosis and treatment. When achieving seamless integration with the surface of the heart, soft bioelectronic materials can monitor key parameters, including cardiac volume, pressure, and electrophysiological signals in real time through embedded electronic components. These parameters are crucial for the accurate diagnosis of cardiac diseases such as ischemic heart disease, arrhythmia, and heart failure. Furthermore, by integrating electrical and optical stimulation units into soft bioelectronic materials, it is possible to further optimize the therapeutic outcomes of cardiac electrophysiological treatments. This review systematically summarizes recent advances in soft bioelectronic materials for the diagnosis and treatment of cardiac diseases, with a focus on current challenges and future directions in this field.