Positioning and clamping device

The embodiment of the invention provides a positioning and clamping device which is used for flange plate drilling of a flange yoke of a transmission shaft. The positioning and clamping device comprises a base, a drill plate, a positioning block assembly and a locking mechanism, wherein the base comprises a substrate and a pair of supporting pieces erected on the substrate, and the pair of supporting pieces are oppositely arranged at intervals; the drill plate covers the pair of supporting pieces, and drill bushings used for drilling holes are embedded in the drill plate; a containing space is defined by the pair of supporting pieces, the drill plate and the substrate together; the positioning block assembly is arranged in the containing space and comprises a V-shaped block, and the V-shaped block and the drill plate are arranged in a spaced mode; the V-shaped block is movably connected with the supporting pieces in the vertical direction; and the locking mechanism comprises a locking piece and a handle. The