When the general magnetic liquid sealing device is used for the highspeed rotating shaft seal,due to the influence of centrifugal force,a large number of magnetic fluids are transferred,resulting in deterioration of sealing performance.Meanwhile,in the process of highspeed rotating,the increase of temperature and the decrease of viscosity of the magnetic fluid because of a large amount of heat generated by friction damage the sealing performance of magnetic liquid.A new highspeed magnetic fluid sealing structure was designed,which eliminated the effect of centrifugal force on the magnetic fluid by changing the mutual position of rotating and static sealing magnetic poles of the general magnetic liquid sealing device,decreased the temperature of magnetic fluid by adding a nonferrous sleeve to accelerate heat transfer.The geometric parameters of the key parts of the seal were optimized,and the radial size of magnetic pole and permanent magnet and the axial length of the permanent magnet were determined.After optimization,the seal structure has more uniform magnetic flux density distribution in the sealing gap,larger magnetic flux density gradient,and better sealing performance.By using ANSYS,the distribution of magnetic flux density of the highspeed magnetic fluid sealing structure and the pole tooth was simulated.The simulation result validates the rationality of sealing structure optimization.