A numerical control lathe with an automatic punching device in particular relates to structural improvement of a tail seat punching device of a numerical control lathe. The numerical control lathe with the automatic punching device is convenient to operate, low in labor intensity, high in production efficiency and high in drilling accuracy. The numerical control lathe with the automatic punching device comprises a machine seat, a lathe body and a tail seat, wherein the tail seat is positioned at one end of the lathe body, a lathe head is arranged at the other end of the lathe body, the tail seat is mainly composed of a tail seat guide rail, a tail seat carriage plate, a tail seat body, a tail seat sleeve and a hydraulic oil cylinder, the tail seat is installed on the lathe body through the tail seat guide rail, the tail seat sleeve is positioned in a round hole of the tail seat, a left linear guide rail or change rail and a right linear guide rail or change rail are arranged on the lathe body on two sides of the tail seat and the lathe head, the carriage plate is positioned above the linear guide rails, a motor seat is arranged on the lathe body under the carriage plate, the lathe head is arranged above the lathe body, the motor seat is positioned on the lathe body, a servo motor is arranged at the front end of the motor seat, the slidable tail seat carriage plate is arranged in the middle of the lathe body, the tail seat guide rail is connected with the tail seat carriage plate, and the tail seat body is connected with the tail seat carriage plate. The numerical control lathe is simple to operate and high in production efficiency.