In order to effectively suppress the spindle heating of machine tool and reduce the influence of spindle heating on machine tool accuracy,a design method of water cooler for spindle thermal control was proposed.According to the distribution characteristics of internal heat source of machine tool spindle,the overall design scheme of machine tool water cooler was formulated,and each functional sub module was developed.Based on the functional analysis of water cooling process,the control principle and method of machine tool water cooler were put forward.The experimental results show that:the machine tool water cooler can reduce the spindle temperature by 30% and the heat balance time by 45%.