In order to study the distribution of magnetic field in the magneticfluidlubricated oilfilm bearings,three different forms of the external magnetic field was exerted through the application of permanent magnet,toroidal solenoid and Helmholtz coils.Twodimensional solid finite element model of magnetic field was established and analyzed to study the magnetic field distribution of three different models.The magnetic field distribution in oil film district for different models was compared.The results show that the magnetic field is different for three different models,it is mainly distributed in permanent magnets,the oil film,bearing pedestal and roll part near the magnet for the permanent magnets model,mainly in the oil film,bearing pedestal and roll part near the magnet for toroidal solenoid model,and mainly in the coil and the end of the oil film for Helmholtz coils model.The magnetic field distribution of the three different models in oil film district has an end effect and presents uneven distribution along the axial,which is small in the middle and large at ends.The magnetic field distribution in oil film district is uniform along the radial direction for the permanent magnet model and toroidal solenoid model, but not uniform for the Helmholtz coils model.