Main motion of CNC horizontal machining centers is driven by gears transmission system via two-step speed change to increase torque of spindle. The bearings of spindle adopt imported bearings to provide the spindle with high speed and good rigidity. Machines with higher speed of spindle are supplied with cooling cycle unit to control spindle temperature. Two kinds of rotary worktable are available for selecting i.e. indexing rotary worktable and NC rotary worktable. The NC rotary worktable adopts angular encoder for direct measurement with characteristic of high accuracy. The double exchanging pallet is supplied for standard configurations to accompolish auto exchanging of pallet, resulting in reducing assistant time and increasing efficiency. The machine is equipped with square-type harden guide-ways to ensure high stiffness and long service time of the machine, and linear rollers of high rigidity are provided for higher speed travel. Machines of this series have perfect functions with steady accuracy, suitable for machining all kinds of box-type work-pieces and two-dimension or three-dimension curved surfaces. Thus they are key equipments for the industries of machine, automobile, shipping, textile and press mechanism, agriculture machinery etc.