Assembling tool for normal position integration of lower assembly of large aircraft and construction method of assembling tool

The invention discloses an assembly tool for normal position integration of a lower assembly of a large aircraft and a construction method of the assembly tool, and belongs to the technical field of civil aircraft production and manufacturing process equipment. According to the assembly tool for normal-position integration of the lower assembly of the large aircraft and the construction method of the assembly tool, the number of tools is relatively small, and the assembled lower assembly does not need to be turned over. The assembling tool comprises positioners, the assembling tool further comprises a supporting framework and a positioning base frame assembly, and at least one part of the positioners are arranged on the supporting framework through the positioning base frame assembly; in the normal-position integration process of the large aircraft lower assembly, a bulkhead and a skin of the large aircraft lower assembly are positioned and fixed through the positioner under the cooperation of the positioning