The utility model discloses a nut main-driving ball screw pair. The nut main-driving ball screw pair comprises a lead screw, a nut, a nut base, a bearing mechanism and a driving motor, wherein the nut base is arranged on the nut in an embedded mode through the bearing mechanism so that the nut can freely rotate in the circumferential direction relative to the nut base, the nut is connected with the driving motor through a transmission device, and the nut base is integrally connected with a workbench. The nut main-driving ball screw pair is small in rotation inertia and large in rigidity, the limit speed of the system is greatly increased, and low-speed operation and high-speed transmission can be achieved easily; meanwhile, the working accuracy is stable, the power of the motor is small, and the nut main-driving ball screw pair is simple in overall structure and convenient to install and adjust.