Main lifting system of large-tonnage gantry crane

The invention discloses a main hoisting system of a large-tonnage gantry crane, and relates to the technical field of crane hoisting systems, the main hoisting system comprises a winding drum, a driving mechanism, a pulley block and a steel wire rope, the winding drum is installed on a trolley frame and connected with the driving mechanism, and a guide pulley is further installed on the trolley frame and located on the side, away from the winding drum, of the pulley block; the steel wire rope is discharged from the winding drum, bypasses the guide pulley, is redirected by the guide pulley and then is wound on the pulley block, and the bottom end of the pulley block is connected with the lifting hook group; through the arrangement of the two groups of guide pulleys, the problem that the minimum deflection angle of the steel wire rope of the multilayer winding fold line reel is less than 0.5 degree in the lifting process of a lifting hook is avoided, and meanwhile, the deflection angle of the rope outlet end of