The invention relates to the technical field of punch forming of high-rigidity plates, in particular to a compact high-rigidity oblique wedge mechanism. According to the compact high-rigidity oblique wedge mechanism, an upper sliding plate and a baffle are connected to a sliding block base, a compact powerful nitrogen spring is connected to a sliding block, and the sliding block base and the sliding block are connected through two lateral sliding plates, so that an execution unit of the oblique wedge mechanism is formed; a V-shaped guide plate and a driving block are connected to form a driving unit of the oblique wedge mechanism; and the driving unit is connected with the execution unit through an inverted wedge pulling plate and drives the execution unit to achieve punching of the high-rigidity plates through the compact high-rigidity oblique wedge mechanism. The compact high-rigidity oblique wedge mechanism has the advantages that high-rigidity materials are used as main materials of the oblique wedge mechanism, so that the rigidity of the oblique wedge mechanism is remarkably improved by two times or over; an oil filling port and a double-ring oil groove are designed, so that the friction coefficient between friction pairs is obviously decreased; and a semi-circular structure is used for optimization treatment of the sliding fit positions of the lateral sliding plates and the sliding block, the angle of the V-shaped guide plate is designed to be increased, and thus the rigidity of the oblique wedge mechanism is remarkably improved.