By using the space error compensation technology, the space positioning accuracy of CNC machining tools should be enhanced effectively. Taking a precision horizontal machining center as target, the key questions and total solution on geometry errors compensation were expounded systematically. Through the threedimensional error modeling and analyzing on the target machining tool, seventeen errors needed be measured and compensated in total twentyone errors, else four had little influence on the machine tool positioning accuracy. Based on this result, the geometry errors measure and compensation scheme were designed, and the fundamental error measure method and error compensation results were provided. The results show that after a systematic error measurement and compensation, the spatial positioning accuracy of the precision horizontal machining center can be improved by 50%~70%; planning and implementing these space errors measure reasonably, the measure efficiency can be increased greatly.