Abstract: A magnetic liquid sealing device includes a housing, a rotating shaft, a first pole shoe, a second pole shoe, a plurality of permanent magnets, a rotation ring, and a sealing block. A chamber is defined in the housing including a first housing and a second housing. The rotating shaft passes through and is rotatable. The first pole shoe and the second pole shoe surround the rotating shaft and are spaced apart. The plurality of permanent magnets between the first pole shoe and the second pole shoe are spaced apart. The rotation ring surrounds the rotating shaft and is rotatable. The first housing, the rotation ring, and the second housing define the chamber. The rotation ring on outer sides of the plurality of permanent magnets is defined with a through hole running through the rotation ring. The sealing block in the through hole is detachably connected to the rotation ring.