In order to effectively control the thermal deviation of the spindle,the thermal characteristics of the spindle system of CNC horizontal milling and boring machine were analyzed,and a spindle thermal offset control method based on shunt component cooling was proposed.The cooling oil circuits with different flows were designed to ensure that the heat of the spindle bearing was effectively taken away,and then the thermal elongation of the spindle was controlled,and the test verification was performed on the prototype to determine the effectiveness of the method.