Abstract: Magnetic fluid seal has the self restoring capacity after bursting. The anti pressure capacity of magnetic fluid seal after restoring is importent for application. The self restoring process was observed. The influence of increasing rate of pressure, the bursting times of magnetic fluid seal, magnetic field gradient under sealing teeth, the number of sealing teeth on magnetic poles, and the number of magnetic poles on anti pressure capacity of restored magnetic fluid seal was studied. Some conclusions valuable for increasing self restoring capacity of magnetic fluid seal were summarized.