The invention discloses an end-face machining clamping mechanism for a gear reversing and gear shifting cantilever. The end-face machining clamping mechanism comprises a bottom plate, a locating base, locating base supporting blocks, a first clamping mechanism, a sharing pressing mechanism, a second clamping mechanism and lifting rings. The first clamping mechanism comprises a workpiece installation block, a V-shaped locating block, a limiting and fixing block, an elastic ejecting mechanism, a locking and fixing block, a lever-type oil hydraulic cylinder and a locking screw. The structure of the second clamping mechanism is completely the same as the structure of the first clamping mechanism, and the second clamping mechanism is rotated by 180 degrees relative to the first clamping mechanism to be installed. The sharing pressing mechanism comprises an oil hydraulic corner cylinder and a pressing plate, and semicircular notches are formed in the two ends of the pressing plate. The end-face machining clamping mechanism is applied to a vertical machining center, and a workpiece can be rapidly and accurately clamped and located. The two clamping mechanisms are operated by one person, the number of clamps and the number of clamping times are decreased, the working efficiency is improved, and the labor cost is reduced.