The invention discloses a plate punching mechanism, which belongs to the field of material processing mechanical equipment. The invention includes a fixed bracket, a punching bracket, a guide roller, a bearing bracket, a bearing cylinder, a translation bracket, a lower translation plate, an upper translation plate, a punching cylinder, a drilling motor and a punching rod, and the bearing bracket is horizontally arranged on the On the fixed bracket between the two guide rollers, the output end of the bearing plate cylinder is fixed to the lower side of the bearing plate support, and the upper side of the bearing plate support is evenly rolled. A plurality of bearing plate rollers are installed, and the lower translation plate slides along the horizontal direction and is set on the lower translation Guide rod, the upper translation plate is horizontally arranged on the upper side of the lower translation plate, the upper middle part of the upper translation plate is vertically provided with a punching cylinder downward, and the output end of the punching motor is vertically provided with a punching rod. The invention has a reasonable structural design, and can quickly and conveniently translate, rotate, and compress and fix plates of various sizes and specifications, so that the plates can be punched efficiently and accurately to meet the needs of production and use.