In order to solve the problems such as difficulty of four-axis linkage interpolation of horizontal four-axis machining center, the lock displacement change of the rotary axis caused by structural problems, the rotation collision when returning to the origin, stop collision during processing, through practice accumulation and research on post-processing, based on UG POST software and the TH6350 horizontal machining center produced by Shenyang Machine Tool Factory, using the TCL language as the development environment, all-round post-processing customization was carried out to solve the above problems. The key problems in the construction of such post-processing were described in detail, and the core algorithm program was disclosed. Finally, the feasibility, integrity and stability of the post-processing are verified through the actual processing of the Hercules Cup, which provides reference for the post-processing customization scheme and processing technology for double-station horizontal machining center.