The motorized spindle supported by hydrostatic bearing is one of the most critical components of the high precision CNC machine tools. The pressure distribution, stiffness and temperature field distribution of the oil film directly affect the machining accuracy of NC machine tools. Based on hydrostatic technology theory, the flow rate and hydrostatic cavity pressure and stiffness of the bearing were calculated numerically. Based on the ANSYS FLUENT co simulation platform, taking the lubricating oil film of hydrostatic radial bearing as the research object, the pressure field, flow field and temperature field distribution were studied including the static and transient status. The simulation results and the numerical results obtain a very good consistency. Analysis shows that the pressure and temperature distribution of the lubricating oil in the hydrostatic cavity have no significant change when the spindle speed changes and circumferential and axial sealing edges are the position where the pressure and temperature change sensitively.