The principle of the HSDB R hybrid bearing for a high efficiency and precision spindle was described,and the hydrodynamic equations of bearing oil film were established based on Navier Stokes equations.The effects of bearing structure variables and working parameters on bearing performances,such as stiffness and temperature were analyzed by the three dimensional hydrodynamic simulation software FLUENT.The stiffness and temperature distribution of the bearings with straight cavity and turning cavity was compared.The results show that the straight cavity bearing provides larger stiffness and bearing capability,and the turning cavity bearing has low bearing temperature rise.