The invention discloses a double-
coating magnetic liquid sealing device. The sealing device comprises a shell, a rotating shaft, a first pole shoe, a second pole shoe and a first permanent
magnet, wherein a shaft chamber is formed in the shell; the rotating shaft is rotationally arranged in the shaft chamber; a first non-
magnetic coating is arranged on the outer circumferential surface of the rotating shaft; the first pole shoe and the second pole shoe are arranged on the rotating shaft in a sleeving mode and are arranged at intervals in the axial direction of the rotating shaft; second non-magnetic coatings are arranged on the inner circumferential surface of the first pole shoe and the inner circumferential surface of the second pole shoe; the first permanent
magnet is arranged on the rotating shaft in a sleeving mode; the first permanent
magnet is located between the first pole shoe and the second pole shoe; a first liquid cavity is formed among the first pole shoe, the second poleshoe, the first permanent magnet and the first non-
magnetic coating; and the first liquid cavity is used for storing magnetic liquid. According to the double-
coating magnetic liquid sealing device, the
machining difficulty and cost are reduced, the magnetic liquid can be supplemented in time, the
pressure resistance of the magnetic liquid sealing is maintained, the magnetic liquid further has a lubricating effect, and the torsion moment of the magnetic liquid sealing is reduced.