The utility model relates to the technical field of electrolytic cell maintenance, in particular to a tool for hoisting an upper platform of a large electrolytic cell, which comprises a support frameand a flexible bus support mechanism, wherein the support frame comprises a cross beam; the bracket I is fixedly arranged on the cross beam; the bracket II is fixedly arranged on the cross beam; the bracket I and the bracket II form a V shape; the lifting lugs are fixedly arranged at the two ends of the cross beam; the number of the supporting frames is two. The two support frames are arranged inparallel; the flexible busbar supporting mechanism comprises a supporting bracket, one end of which is abutted against one side of the stand column and supported on the upper side of the stand columnseat, and the other end of which is supported below the busbar; the steel wire rope is connected between the other end of the bracket and the hook; the hook is hooked at the upper end of the upright post; the roller skating groove is formed in the steel wire rope. The lifting device can lift the upper platform of the large electrolytic cell, is simple to operate, safe and reliable, and can improvethe working efficiency.