This article introduces the main task and trend of post processing of 5-linkage CNC machine. The kinematics model of 5-axis linkage CNC machine with two rotary tables was established by using the theory of mechanism and homogeneous coordinate transformation. The distribution of linear coordinate transformation and the rotate angle of machine tools were deduced by analyzing the kinematics model. Referencing above formulae, the machine’s post processing program was compiled in SOLIDCAM according to specific machine’s structure. The NC code of impeller was generated by it, and simulated it in VERICUT. The program has past the verification on TDNC-W200. The trend of post processing was got after analyzing the problem of it at last.