With the high prevalence of cardiovascular diseases in modern society, there is a growing demand for effective diagnostic methods. In addition to the traditional electrocardiogram (ECG), magnetocardiography (MCG), as an emerging non-invasive diagnostic technique, has attracted increasing attention. Although mature ECG simulators for medical research are already available on the market, there is still a lack of dedicated simulation equipment for MCG, which hampers experimental validation of MCG-related algorithm research. Therefore, this paper proposes a time-sequence-controlled cardiac magnetic field simulator (CMFS), which utilizes a multi-channel programmable current source to flexibly generate source currents corresponding to a cardiac equivalent current dipole with known parameters, reflecting the heart’s electrophysiological activity. The current dipole simulators are embedded at different positions within a physical heart model to simulate the spatial distribution of the cardiac magnetic field. This simulator has the potential to support research on MCG inverse algorithms, and the design concept presented in this paper is expected to serve as a reference for the development of cardiac magnetic field simulators.