To study the magnetic field characteristics in a non-contact mechanical seal lubricated by the magnetic fluid,the magnetic field intensity and the magnetic induction intensity in the sealing system were numerically simulated by Ansoft Maxwell.The effects of the magnetic fluid film thickness and the current intensity on the magnetic field intensity and the magnetic induction intensity were analyzed,and the relationship between the magnetic induction intensity and the current intensity in the magnetic fluid film was fitted by the last square method.The results indicate that the magnetic induction lines appear as complete “O” loops in the whole sealing system,and the magnetic induction intensity in the magnetic fluid film is the largest.The magnetic induction lines pass through the magnetic film vertically and evenly.When the current intensity is constant,both the magnetic induction intensity and the magnetic intensity are constant along the film thickness direction,both of which increase with the increase of current intensity.