The guide-ways for CNC vertical machining center series adopt cast iron with hardening process to provide high rigidity and long service-time. Main motion of large-scale CNC vertical machining center is driven by gears transmission system via tow-step speed change to provide the spindle with increased speed range and large torque, suitable for power cutting. The bearings of spindle adopt imported bearings with characteristics of high speed and good rigidity. The bed is supplied with cooling cycle unit to control spindle temperature, and the machine bed is provided with four guide-ways to obtain high rigidity for the whole machine set. Machines of this serried are suitable for high accuracy machining such as milling, drilling, counter-boring, reaming, boring, and tapping for two-dimension of three-dimension curved and sloping surfaces.