Disclosed is a vertical direction drive system of a numerical control milling and boring machine. The vertical direction drive system of the numerical control milling and boring machine is characterized in that a stand column of the machine is vertically and fixedly connected with a connecting plate, the upper portion of a lead screw which is parallel to the stand column is vertically fixed with one end of the connecting plate through a transition flange, the connecting plate is further provided with a servo motor and a speed reducer, the output end of the connecting plate is coaxially fixed with the upper portion of the lead screw, the upper end of the speed reducer is coaxially and fixedly connected with a flange plate and an electromagnetic type safety brake, and the electromagnetic type safety brake is coaxially connected with the upper end of the lead screw through a key; a screw nut is arranged in the middle of the lead screw, a concentric spindle box is arranged above the screw nut, and a falling prevention structure is arranged inside the screw nut; the lower end of the lead screw is fixedly connected with a bearing through a lock nut, and a bearing pedestal is fixed with the bottom of the stand column through a screw; pressing plates are fixed on the spindle box, the spindle box is attached to the front faces of guide rails of the stand column, and the two pressing plates are attached to the back faces of the two guide rails of the stand column respectively; when design is conducted before manufacturing, the application condition of the drive system on the machine is considered, the corresponding speed reducer, the lead screw, the servo motor and the electromagnetic type safety brake are selected according to calculated technical parameters, and the drive system has the advantages that the balance weight of the spindle box is removed, and quadruple safety protection is achieved.