Prefabricated part gantry hoisting device and using method

The invention relates to a prefabricated part gantry hoisting device and a using method. The prefabricated part gantry hoisting device comprises two tracks, supporting stand columns, a connecting cross beam, a hoisting rod, a top derailing prevention device and a bottom derailing prevention device. The two tracks are arranged in parallel; the supporting stand columns comprise the left supporting stand column and the right supporting stand column; the left supporting stand column and the right supporting stand column are identical in structure; the bottom of the left supporting stand column and the bottom of the right supporting stand column are movably arranged on the tracks through the bottom derailing prevention device correspondingly; the top of the left supporting stand column and the top of the right supporting stand column are connected through the connecting beam; the left supporting stand column, the connecting beam and the right supporting stand column jointly form a portal frame; the portal frame sl