The research of magnetic separation starts from magnetic solid particles to nanoparticles, and in the research progress, particles become smaller gradually with the development of application of magnetic separation technology. Nevertheless, little experimental study of magnetic separation of molecules and ions under continuous fl owing conditions has been re-ported. In this work, we designed a magnetic device and a“layered”fl ow channel to study the magnetic separation at the ionic level in continuous fl owing solution. A segregation model was built to discuss the segregation behavior as well as the factors that may affect the separation. The magnetic force was proved to be the driving force which plays an indispensable role leading to the segregation and separation. The fl ow velocity has an effect on the segregation behavior of magnetic ions, which determines the separation result. On the other hand, the optimum fl ow velocity which makes maximum separation is related to the initial concentration of solution.