The thermal deformation control and thermal error compensation technology for horizontal machining center were studied from three levels of reducing heating,controlling temperature rise and thermal error compensation.At the first level,the heating of machine tool was reduced from the selection of high precision functional parts and lubrication technology.At the second level,the effect of cooling in controlling the temperature rise and balancing the temperature field of the key components was studied from the aspects of spindle temperature control,temperature control of hollow screw,temperature control of structure foundation,etc.At the third level,the thermal error compensation technology was studied from data acquisition,analysis,modeling and so on.The specific techniques and measures of controlling thermal deformation and thermal error at various levels were used in the practical products,and good application results were obtained.