Based on JT-GL8-V five axis machining center equipped with HNC848B CNC system, a corresponding UG post processing program was developed to solve the five axis processing core technical problems, such as pre-rotation of five axis machine center table, over travel of A axis, feeding and program connection. A simulation platform was established by using VERICUT software; the post processing program was used to generate two typical parts processing programs.Through simulation and actual machining, the five axis post processing is verified to be safe and reliable,it can meet the machining requirements of directional machining, drilling and five axis linkage.