The present disclosure relates to a magnetic liquid sealing device. When a rotating shaft of the device axially vibrates, an outer ring of a bearing may not be provided with a rim, and a J-shaped bush and U-shaped sleeve ring can have relative displacement in an axial direction. When the rotating shaft radially vibrates, the U-shaped sleeve ring may deviate radially to allow sealing gaps, so as to prevent a bump between a pole shoe and J-shaped bush. Under action of a support spring and axial spring, sealing rings can be pressed to allow for sealing, and the U-shaped sleeve ring may not be in direct contact with an end cap, so as to avoid face friction.