Flexible thin plate punching device

A flexible thin plate punching device comprises a machine frame, a punching table, backing rings, a punching pressing head, a pressing mechanism and hydraulic oil cylinders, the machine frame is provided with the punching table and a plurality of hydraulic oil cylinders correspondingly located above the punching table, the backing rings are arranged on the top face of the punching table in the length direction, inner holes of the backing rings correspondingly face the hydraulic oil cylinders, and the hydraulic oil cylinders are arranged on the top face of the punching table. The top surface of the backing ring is used for placing a thin plate; the hole diameters of inner holes of the backing rings are different, a trepanning pressing head is correspondingly arranged above each backing ring, the multiple trepanning pressing heads are connected with the multiple hydraulic oil cylinders in a one-to-one correspondence mode, and the tool bit ends of the trepanning pressing heads can be matched with the inner holes