Abstract: As a consequence of the gradual depletion of high-quality iron ore resources in China, the existing iron ore resources exhibit the characteristics of “poor, fine, miscellaneous”, which renders mineral sorting increasingly challenging. In this context, high-gradient magnetic separation is of great significance, as it allows for the improvement of the recovery of difficult-to-select iron minerals through the enhancement of magnetic field strength, the synergy of multi-physical fields, and the optimization of magnetic aggregation media. This paper reviews the application of high-gradient magnetic separators with different excitation systems (permanent magnetic, electromagnetic and superconducting) and the progress in the study of polymagnetic media. The utilization of novel permanent magnetic materials in permanent magnet high gradient magnetic separators has been demonstrated to augment the magnetic field strength and stability of the equipment, thereby effectively enhancing the mineral capture ability. An electromagnetic high-gradient magnetic separator can be classified into two categories, namely wet and dry, depending on the processing of weak magnetic minerals. A wet magnetic separator primarily addresses the issue of media clogging through the utilization of water media, whereas a dry magnetic separator employs airflow to enhance the sorting process and mitigate the electrostatic effect, thereby optimizing the overall sorting efficacy. A superconducting high gradient magnetic separator offers a robust magnetic field strength through the incorporation of superconducting materials, thereby reinforcing the sorting of weak magnetic minerals. However, it necessitates a low-temperature environment. In recent years, notable advancements have been made in this field, including the introduction of a novel cooling system and the development of a pulp pulsation structure. Furthermore, the magnetic permeability and durability of diverse polymagnetic media are exhaustively delineated, and the benefits and drawbacks of spherical, steel wool, toothed plate, and bar media in sorting are contrasted. The effects of media arrangement on magnetic field strength and capture effect are further explored, as well as the effects of media filament diameter and different cross-sectional shapes on magnetic field properties and sorting performance. In conclusion, the prospective research direction of the high gradient magnetic separator and the optimisation of the polymagnetic medium are discussed, with the objective of providing a reference for the technological progress in the field of high gradient magnetic separation.