The invention discloses an ultrahigh vacuum magnetic fluid seal transmission device. The ultrahigh vacuum magnetic fluid seal transmission device comprises a shell, a seal
assembly and bearings; the seal
assembly comprises a main shaft, a permanent
magnet, a first magnetic pole, a second magnetic pole and magnetic fluid, wherein the first magnetic pole and the second magnetic pole are arranged at the two sides of the permanent
magnet, the magnetic fluid is arranged between the main shaft and the first magnetic pole and / or the second magnetic pole, and the seal
assembly is arranged between the ultrahigh vacuum side and all the bearings; a first seal type cavity is arranged on the contact surface between the first magnetic pole and a
flange of the shell, a first
metal sealing
gasket is arranged in the first seal type cavity, and after the first
metal sealing
gasket is compressed to be deformed by the
axial force between the
flange and the first magnetic pole, the
flange and the first magnetic pole are sealed. The ultrahigh vacuum magnetic fluid seal transmission device has the advantages of being stable in seal, high in limiting vacuum, low in
leak rate, low in gas permeability, large in pumping rate and free of vacuum
pollution.