Based on the structure of 6 - TPS parallel kinematic machine tools (PKMTs) with 6 degrees of freedom (DOF), the theory and procedure to generate control data is introduced. On the basis of above analysis, the functions and framework of a postprocessor for this type of machine tools is designed. Some important methods for carrying out the postprocessing of the machine are researched and demonstrated, including inner data transfer protocol by parameterized binary data, interpolating algorithm in Descartes coordinate system, planar and spatial tool radius compensation, preprocessing of cutter location data, and word and syntax check of machining codes. Finally, a real machining experiment on the system mentioned above is introduced. The result shows that it can be successfully used in real manufacturing environment.