In view of the difficulty of existing sealing methods to solve the sealing problems caused by high linear velocity of rotating spindle of centrifugal compressor,a new magnetic fluid sealing device with temperature and pressure reduction function was designed,and the calculation formula of pressure resistance of magnetic fluid rotating dynamic seal considering the influence of centrifugal force was established based on the motion equation of magnetic fluid.The distribution law of magnetic induction intensity in the sealing gap of this sealing device was studied by using finite element numerical analysis method.The influence of of various structural parameters on the seal performance was analyzed,and the key structural parameters were optimized by using orthogonal test and response surface optimization method.The results show that the centrifugal force has a significant effect on the sealing performance when the linear speed of the rotating shaft is high.The sealing pressure value first increases and then tends to stabilize with the increase of the thickness and width of the permanent magnet,it decreases with the increase of the sealing gap,and first increases and then decreases with the increase of the tooth width,tooth height and slot width.The degree of influence of each parameter on the sealing performance,in descending order,is sealing gap,tooth width,slot width,permanent magnet width,tooth height,permanent magnet thickness.The structural parameters of the optimized magnetic fluid seal are sealing gap 0.1 mm,pole tooth width 1.274 mm,tooth height 1.8 mm,slot width 2.236 mm,permanent magnet thickness 7 mm and permanent magnet width 20 mm，and the optimized sealing pressure value is 0.721 MPa,which is much higher than the seal pressure value required by the working condition.