The work aims to carry out regularity study and experimental verification on the size and curvature of magnetic pole plate to solve the non-uniformity and low efficiency in deburring of throttling edge of spool parts. Firstly, the Maxwell software was used to simulate the changes in different parameters of magnetic pole plate, and then the appropriate size of the magnetic pole plate was obtained. Secondly, in order to improve the magnetic induction intensity in the processing area, curved magnetic pole plate was designed, and the related parameters were simulated and analyzed. Finally, the magnetic induction intensity of the improved device was measured, and the edge burrs of 45 steel and spool were removed by fluid magnetic abrasive. According to the simulation results, when the length of the magnetic pole plate was 20 mm larger than the workpiece, the axial magnetic field distribution of the workpiece was the most uniform, and the thickness of the magnetic pole plate had little influence on the magnetic field. The width of the magnetic pole plate should be selected according to the machining gap. The magnetic induction intensity in the processing area could be enhanced by the curved magnetic pole plate. The smaller the radius of curvature was, the larger the value of magnetic induction intensity was, among which the semicircular magnetic pole plate had the best effect. The magnetic induction intensity test of device showed that after the workpiece was placed in the field, the magnetic induction intensity of the spool surface in the processing area could reach up to 600 mT, which met the processing requirements. Finally, it was found that when the speed of workpiece reached 500 r/min, the deburring effect of throttling edge of spool parts was ideal and the axial processing was even. The device has good processing effect on the magnetic rotating parts such as spool.