This paper investigates the accuracy evaluative factors of 5-axis turbo molecular pump rotor machining center.Using rigid body kinematics techniques and homogenous transformation matrices, the systemic geometric volumetric error model are established for error synthesis. Novel volumetric accuracy model can be verified effectiveness better estimation of machine performance, by means of physical simulation and measurement. The effect of the individual axis geometric errors can become increasingly significant as the chain of dependent axis is extended. The effect of the rotary axis and their errors cannot be ignored. Calculating volumetric accuracy as the maximum difference between the error vector at any two positions can be computationally intensive.