A magnetocardiograph (MCG) is a high-sensitivity magnetic field detection sensor based on a low-temperature superconducting quantum interference device. It measures the distribution of magnetic field parameters of the cardiac magnetic field (target magnetic field) in the plane directly above the human chest. Through complex magnetic field inversion algorithms, it obtains the isomagnetic map and current density distribution of the most active plane of the target source (heart). By analyzing and extracting electrophysiological-related indicators and parameters, it completes the classification of abnormal cardiac electrophysiology, as well as the diagnosis of myocardial ischemia and myocardial injury based on cardiac electrophysiological models and statistical methods. The quality of the signals from the magnetocardiograph is crucial to ensuring the accuracy of diagnosis and classification results. This paper will introduce the research on how to evaluate the signals collected by the magnetocardiograph and the evaluation criteria, and their application in practical clinical settings.