In view of the problems of traditional mechanical seal such as large resistance,short life and poor applicability of axial magnetic liquid seal,a new axial and diameter combined magnetic liquid seal structure was designed according to the characteristics of high speed and heavy load of rotating parts of mining equipment.The size parameters of key components in the sealing structure were optimized.The magnetic field characteristics of the combined and single axial seal structures were simulated by ANSYS software,and the sealing performance of the two seal structures was compared.The results show that the structure design of the new axis-diameter combined magnetic liquid seal is reasonable,which can effectively avoid the failure problem of the high-speed rotating shaft seal caused by centrifugal force,and the pressure resistance of the new shaft-diameter combined magnetic liquid seal is increased by 52.7% compared with the single axial magnetic liquid seal structure,which verifies the reliability of axis-diameter combined seal structure.