A punch device of a notching machine comprises a working table and further comprises a material containing table, a support, a motor, a linkage mechanism and a cutter which are arranged on the working table. The support is obliquely arranged in front of the material containing table and provided with a slide rail. The linkage mechanism is arranged on the support. One end of the linkage mechanism is connected with the motor, and the other end of the linkage mechanism is connected with the cutter. A groove used for containing raw materials is formed in the material containing table. The cutter is obliquely arranged above the groove and fixedly connected with a slide block. According to the punch device, cutting is achieved in the manner that the linkage mechanism drives the obliquely-arranged cutter, stress of the raw materials at all angles is more balanced, power required for cutting is smaller, the automation degree and the work efficiency of cutting are improved, and safety of operators is ensured.