Abstract: In order to investigate the magnetic properties variation tendency of the diamond magnetic media with the change of the vertex angle，ANSYS software is used to simulate the magnetic field characteristics at different diamond vertex angle and various background magnetic field strength.The results show that when background magnetic field strength is 0.2T，the magnetic field intensity，magnetic field gradient and magnetic field force reduce with the increase of α angle.When background magnetic field strength is more than 0.2 T，magnetic field intensity，magnetic field gradient and magnetic field force present tendency of first increase and then reduce with the increase of α angle.In addition，when α angle is less the extrema，the magnetic field intensity，magnetic field gradient and magnetic field force increase slowly，when α is more than the extrema，decrease rapidly.With the increase of α angle，the effective magnetic flux area will increase.This is helpful to improve medium magnetism gathering ability.The relative result is the increase of the magnetic field intensity，magnetic field gradient and magnetic field force，while the effective magnetic flux area is too big，magnetic line of force distribution will be more scattered，result in the reduce of the magnetic field intensity，magnetic field gradient and magnetic field force.With low background magnetic induction intensity，the magnetism gathering ability is always less than the effect of dispersion force，magnetic field intensity,magnetic field gradient and magnetic field force slowly decline and then rapidly decline；With high background magnetic field intensity，alpha is smaller than a certain angle，disperse magnetic effect is greater than the assembled magnetic force，and when alpha is bigger than a certain angle，disperse magnetic effect is smaller than the assembled magnetic force，greater than this angle，the assembled magnetic effect is less than the magnetic force，magnetic field intensity,magnetic field gradient and magnetic field force slowly increase when alpha is smaller than a certain angle，and falling fast when alpha is bigger than a certain angle.

Key words: Diamond magnetic media, Vertex angle, Magnetic field intensity, Magnetic field gradient, Magnetic field force, Effective magnetic flux area