The invention relates to the field of food processing devices, in particular to a pressing and shearing mechanism of a corn dog shearing machine. The pressing and shearing mechanism comprises double-wheel tensioning mechanisms, single-wheel tensioning mechanisms, pressing assemblies, a drive wheel mechanism, a shearing device, a drive belt, a driven wheel, a drive device and a machine frame. An arc-shaped first nylon bracket is arranged in the machine frame. The single-wheel tensioning mechanisms are evenly distributed in the arc direction concentric with the first nylon bracket. The adjustable double-wheel tensioning mechanisms and the adjustable pressing assemblies are alternately arranged in the arc direction concentric with the first nylon bracket between the single-wheel tensioning mechanisms and the first nylon bracket. An arc-shaped passageway used for conveying dog bodies is composed of the double-wheel tensioning mechanisms and the first nylon bracket. The shearing device is arranged at the output end of the arc-shaped passageway. The closed drive belt sequentially passes through the double-wheel tensioning mechanisms and the single-wheel tensioning mechanisms in an alternate mode after passing through the drive wheel mechanism and the driven wheel. Shearing is neat by pressing the dog bodies, and the production efficiency is improved.