Abstract A model of spiral oil wedge hydrodynamic bearing is first established, and a numerical simulation of the fluid region is carried out by Fluent. The influence of inlet pressure and rotation speed on the cavitation area in the oil film divergence region is analyzed, and the cavitation shape, size, and location of the cavitation area are also compared and analyzed; at the same time, the influence of noncondensing gas (NCG) mass fraction on the oil film flow field is studied. The results show that the results of the numerical simulation are in agreement with the experimental results. The change of the inlet pressure and rotational speed can affect the disappearing position of the cavitation, but it has almost no influence on the appearing position of the cavitation. The increase of the inlet pressure can reduce the cavitation effectively, as well as the area of cavitation and number of large volume cavitation. But the increase of the rotational speed promotes the production of cavitation obviously and increases the number and area of cavitation and the possibility of complete cavitation. The NCG content in lubricating oil has a certain influence on the lubrication performance and bearing capacity.