After analyzing the structure and kinematics features of 5-axis linkage CNC machine with two rotary tables and one of the rotary axis fixed at angle of 45° to the spindle, the algorithms for the post processing method of cutter location data are proposed and the corresponding formulate of coordinate conversion are deduced, the post processing for non orthogonal 5-axis linkage CNC machine by programming with Tcl language is achieved. The post processor is stable and reliable, and put into practical application.