Abstract: The paradox between centrifugal capture and particle dispersion in traditional external magnetic cylinder magnetic separators led to significant losses of fine−grained concentrate at low rotational speeds, with elevated speeds diminishing both pre−selection tailing rates and concentrate grades. In response, a novel form of external magnetic cylinder magnetic separator was developed to exploit variations in density and specific magnetization coefficients between magnetic and chalcopyrite minerals, enhancing the capture of targeted minerals. Through the implementation of a centrifugal flushing water system on the cylinder's surface, a dynamic control mechanism for capturing and dispersing mineral particles has been successfully realized. COMSOL Multiphysics was used to optimize the magnetic induction intensity, magnetic field gradient parameters and the flow field characteristics of the magnetic system. The effects of sorting cylinder speed, water inlet dynamics, and cylinder inclination on the flow field were investigated. The simulation results indicated that the surface magnetic induction intensity of the magnetic pole was 1.8 T, and the magnetic field lines of the magnetic system were concentrated around the magnetic medium. Moreover, there was a substantial magnetic field gradient (8×10⁻⁷ A/m²) on the surface of the magnetic medium, with minimal reduction, which facilitated the capture of magnetic particles. An advantage of this device was the inclusion of centrifugal flushing water. Adjusting the particle forces through changes in water velocity could provide a theoretical basis for the optimization design of permanent magnet magnetic separators.