The invention relates to the technical field of electromagnetic flow meter production equipment, and particularly relates to a silicon steel sheet punching device for an electromagnetic flow meter. The device comprises a lathe bed body, a punch, a driving air cylinder, a T-shaped connecting head, a punch mounting base, a positioning panel, a floating compressing plate, and press rods. The drivingair cylinder is connected on a top plate; the T-shaped connecting head is connected on the driving air cylinder; and the positioning panel is connected on a bottom plate. According to the silicon steel sheet punching device for the electromagnetic flow meter, the positioning panel is arranged, so that the silicon steel sheet is placed in a upper positioning groove for positioning; a limiting mechanism is arranged for adjusting the punching position of the silicon steel sheet, and realizing the accurate positioning and the punching; a driving cylinder is arranged, for driving the punch to movedownwards, and meanwhile, driving the ejector rods move downwards, and the press rods are continuously close to the floating pressing plate as the punch moves downwards, so that the pressing portion on the float pressing plate can be pressed inside the positioning groove on the positioning panel and pressing the silicon steel sheet; after the pressing, the punch punches the silicon steel sheet andrealizes the automatic punching operation.