Accuracy and efficiency are essential in the CNC machining industry. These are affected by machine rigidity, controller and driver tuning, motion control, spindle speed, machining cutting speed, cutting depth, and tool selections. Efficiency and accuracy are mutually exclusive in classic applications. Changing control and processing method are needed to break through this limitation. This article proposes intelligent controller technologies of program-assisted overlapping control and dual-spindle synchronous learning control. Learning control technology refines the accuracy of dual-spindle synchronous. These can increase machining efficiency without scarifying accuracy.