Though split pole shoe can solve the problems of increased cost and decreased efficiency caused by replacing pole shoes in the test, assembling and use of split sealing devices, it fails to overcome the issue of sealing in the gap between split pole shoe's junction surface and shaft. In this paper, a split magnetic liquid sealing structure is designed, combining magnetic liquid sealing and split pole shoe's plane sealing. In our study, we have adopted three methods for split sealing and use theory and simulation to ascertain the sealing performance of the split magnetic liquid sealing structure designed by us. The results indicate that magnetic sealant bonded split pole shoes show better sealing performance as compared to those bonded by ordinary sealant, and that the structural optimisation results can meet the requirement for sealing performance. The simulation results coincide with theoretical results, which proves the correctness of this research.