Abstract: In order to study the influence of position,strength of electromagnetic field on the medium distribution of dense medium cyclone,take the magnet powder as medium,and the test conducted by placing the dense medium cyclone in the coaxial spiral coil electromagnetic field.The results show that when magnetic field located at the top of the cyclone cylinder,the separation density can be increased by lower magnetic induction,but when magnetic induction located at the bottom of the cyclone cone,the separation density can be decreased by higher magnetic induction.Therefore,the separation density of dense medium cyclone can be adjusted by changing the position and magnetic induction of external electromagnetic field.This may be provided some theories reference for realizing the on-line control separation density of dense medium cyclone.