The invention relates to an energy accumulator leather bag on-line replacing device which is characterized in that the energy accumulator leather bag on-line replacing device comprises an air extracting and inflating device, an energy accumulator assembly, a guiding rod, bag edges and a rope; and the air extracting and inflating device is arranged on the energy accumulator assembly, and the guiding rod is used for guiding radial penetrating of the rope. According to the technical scheme, the use effect is good, safety and reliability are achieved, the environmental destruction accidents such as leather bag bursting and hydraulic oil leakage cannot occur, and energy conservation and environmental friendliness are achieved accordingly.