Locating tool for lower doorsill of main cargo hold door of cargo machine

The utility model relates to the field of aeronautical manufacturing processes, in particular to a positioning tool for a lower doorsill of a main cargo hold door of a cargo machine. The cargo ship main cargo hold door lower doorsill positioning tool comprises a tool body and a groove-shaped piece, the tool body is provided with a datum hole and comprises an L-shaped supporting arm, the datum hole is configured to be fixed to the lower ends of a front frame and a rear frame to form a web face, the L-shaped supporting arm is connected with a sliding rail, and the two ends of the groove-shaped piece are fixedly connected with a floor beam. The upper end of the groove-shaped piece is flush with the lower butt joint face of the old floor beam and the C-shaped connector. The tool body and the positioned lower sections of the front and rear frames form a web face, and it is guaranteed that all joints are located on the same plane. The L-shaped supporting arm is connected with the sliding rail, the whole groove-shap