For major requirements of the domestic highspeed & highprecision large vertical machines,milling machines and other highgrade CNC machine tools,it is urgent to improve their accuracy retention. A rotary table was developed by which largescale highprecision vertical CNC machine tools accuracy retention could be increased. In the rotary table, a set of radial thrust tapered roller bearings were adopted and the conventional spindle and the complex spindle bearing system were eliminated. The bottom ring and the top ring of the radial thrust tapered roller bearings were installed on the same axis table, achieving gapless tight fit among the top ring, the bottom ring and the axis table, eliminating the gaps between all bearing rings and their members,and achieving an interference fit.So the machine tools accuracy retention is greatly improved.