Abstract: This paper proposes a new type of magnetic fluid seal pole tooth profile structure, which can change the sealing gap by moving the shaft sleeve along the axial direction, facilitating the adjustment of sealing gap and sealing ability in practical applications. The pressure resistance formula of magnetic fluid seal was derived, and finite element analysis was conducted by use of Ansys Electronics Desktop software. The results showed that the new polar tooth structure proposed in this paper can effectively improve the performance of magnetic fluid seal. The influences of various structural parameters on sealing performance were carried out by specific examples, and relevant curves of the influence laws were obtained and explained and analyzed. The research results indicate that within a certain range, the smaller the tilt angle, the smaller the sealing gap, the smaller the tooth width, and the larger the tooth groove width, the stronger the sealing ability. The position and tooth height of the permanent magnet have no significant effect on the sealing effect. Through regression analysis, it can be concluded that in practical engineering design, priority should be given to optimizing the sealing clearance and tooth thickness to achieve the best sealing effect.