The utility model provides a one-piece pot conversion device of a medium-high-density battery, which relates to the technical field of the manufacturing of a power lead-acid storage battery. The one-piece pot conversion device of the medium-high-density battery comprises a hollow conversion device body, wherein the conversion device body is a waney cylinder, the upper part of the conversion device body is provided with an insertion groove, the middle part of the conversion device body is provided with an outer threaded section and a sealing gasket, the sealing gasket is arranged at the upper end of the outer threaded section, and the lower part of the conversion device body is provided with an acid adding passage. When acid is added to the storage battery, the one-piece pot conversion device of the medium-high-density battery is used for connecting a one-piece rich-liquor pot and a middle cover of the storage battery, so that a purpose of adding acid to the storage battery by utilizing the one-piece rich-liquor pot can be achieved, not only is the primary acid adding volume increased, but also the consistency of electrolyte in each grid of the storage battery can be guaranteed, simplicity in operation is achieved, the use is convenient, a manual acid replenishing procedure is reduced, and the production efficiency is improved.