Abstract: Immiscible Cu-Co-based alloys are prone to liquid-phase separation during cooling due to their unique metallurgical properties. Traditional fabrication methods often lead to microstructural segregation, and even the formation of layered structures, which limit their industrial applications and hinder the full utilization of their potential superior properties. With the rapid advancement of magnetic field technology, the interaction between high magnetic field and matter has shown to induce unique magnetic effects. This interaction provides a new impetus for the microstructure control of immiscible Cu-Co-based alloys, opening up more possibilities for optimizing their microstructures. In this study, we review research findings on the microstructure control of Cu-Co-based alloys after phase separation under high magnetic fields, both domestically and internationally. The effects of high magnetic fields on liquid-phase separation behaviors of Cu-Co-based alloys during the solidification are analyzed, and the mechanisms of actions of high magnetic fields on melt convection, second-phase growth, and solidification behavior elucidated. Additionally, the optimization effects of high magnetic fields on the phase-separated microstructures of Cu-Co-based alloys are discussed, providing valuable insights for the preparation of other alloy types under high magnetic field conditions.