To provide a wedge ring of a corn crusher which eliminates the bias of wedge ring inputting force and can perform work for adjusting a crushing gap and its mounting structure.

The wedge ring 300 of a corn crusher which is a cylinder which has screws on the inner surface and notch parts over the whole length in the axis direction in a wedge ring 300 which is inserted between the lower part frame 100 of a corn crusher and the upper part frame 120 set in the lower part frame 100 and increases the setting strength of the upper and lower part frames 100, 120 for integration, is screwed with a screw part formed on the peripheral surface of an lower part frame side plate, and is constituted to be able to slide in the axis direction and its mounting structure.