The invention relates to a tool for quickly assembling a pump body. The tool comprises a base, a bracket, a height regulating rod, a radial supporting frame and a supporting rod; the bracket is vertically fixedly arranged at the upper end of the base; the height regulating rod is arranged on the bracket, and can vertically slide along the bracket; the radial supporting frame is arranged at the upper end of the height regulating rod in the radial direction; a plurality of sub brackets are arranged on the radial supporting frame; a radial regulating rod capable of axially sliding along each sub bracket is arranged on each sub bracket; the supporting rod is vertically arranged at one side of the upper end of the base; and a horizontal supporting base capable of vertically sliding along the supporting rod is arranged on the supporting rod. The tool can realize quickly positioning a pump shell and a pump foot with high positioning precision, is convenient for processing in batches, and improves production efficiency.