Positioning and clamping device for welding lifting hook and cylinder

The invention discloses a positioning and clamping device for welding a lifting hook and a cylinder body. The positioning and clamping device comprises a bottom plate, a first positioning assembly anda second positioning assembly. The cylinder body to be welded is suspended above the bottom plate through a support piece, and one end of the cylinder body is fixedly connected with a flange. The first positioning assembly is arranged on the bottom plate and located at the flange end of the cylinder body and comprises a flange supporting block and a flange pressing block, the face, facing the cylinder body, of the flange supporting block is a datum plane, the flange pressing block presses a flange against the flange supporting block, and therefore the cylinder body is positioned. The second positioning assembly is arranged on the bottom plate and located on one side of the cylinder body and comprises a lifting hook support capable of doing reciprocating motion relative to the cylinder body, a first lifting hook s