The invention relates to a numerical control bending machine, a top pressing head and two positioning guide pillars are arranged on a table board of a machine rack, the top pressing head is connected with an oil cylinder, an oil pump is arranged below the table board of the machine rack, the oil pump is connected with an oil pipe and the oil cylinder by a valve to compose a hydraulic transmittingdevice; an electromagnetic valve in the hydraulic transmitting device is electrically connected with a numerical control device, and the numerical control device is composed of a power supply circuit, a control circuit, a drive circuit and an operation circuit. The method of adopting the machine for bending a copper bar is that a software program is inputted in the numerical control device, the copper bar is processed and bent by a top pressure stroke determined by the calculation of the input parameters according to the program; the input parameters are: the thickness of the copper bar to bebent; the horizontal distance between the copper bar to be bent and the lap surface of an upper mother copper bar and a lower mother copper bar; the linear distance between the corresponding edges ofthe upper mother copper bar and the lower mother copper bar; the lap length between the copper bar to be bent and the upper and lower mother copper bars; and the distances from the upper and the lower ends of the copper bar to be bent to the upper mother copper bar and the lower mother copper bar. The numerical control bending machine has the advantages that: the copper bar is processed and bent precisely, so that the numerical control bending machine has no tailing and can save the materials; the processing is simple and convenient, the working efficiency and the processing quality are improved.