Quick positioning and assembling tool for lower vehicle frame

The utility model relates to the technical field of lower vehicle frame assembly tools, in particular to a quick positioning assembly tool for a lower vehicle frame. The quick positioning assembly tool comprises an operation table and a second-stage hydraulic oil cylinder, and the second-stage hydraulic oil cylinder is arranged above the operation table in a fixed structure mode; the second-stage hydraulic oil cylinder comprises a cylinder body, a first-stage piston rod and a second-stage piston rod, the first-stage piston rod is slidably connected with the cylinder body through a telescopic structure, and the second-stage piston rod is slidably arranged in the first-stage piston rod in a sleeved mode through a telescopic structure. A positioning disc of a step structure is arranged at the outer end of the first-stage piston rod in a fixed structure mode, and a through hole allowing the second-stage piston rod to penetrate through is formed in the positioning disc in the axial direction. A clamping groove is