Abstract: In view of the problem that the specific magnetization coefficient of fine-grained weak magnetic iron ore in China is very low and the inclusion rate of conventional high-intensity magnetic sepa⁃ ration technology is high，the structure of a new type of permanent circumferential extrusion magnetic sys⁃ tem was studied. The magnetic force relationship model in the circumferential alternating magnetic pole magnetic circuit was discussed. The three-sided axial extrusion magnetic circuit was extended to the cir⁃ cumferential extrusion magnetic circuit，and the circumferential extrusion magnetic circuit model with high magnetic force and high-speed magnetic flip was established. The permanent magnet high-intensity mag⁃ netic separator with circumferential extrusion magnetic circuit was developed. The separation effect was ver⁃ ified by the separation test of prepared minerals and actual minerals，which lays a technical foundation for the high-precision separation of weak magnetic minerals.

Key words: circumferential extrusion magnet, iron ore with weak magnetic, magnetic flip