The invention discloses an electric backpack water-series fire extinguisher tank body, which comprises a shell, a liquid storing tank and an electromechanical work room, wherein the liquid storing tank is arranged above the shell, and comprises an opening; the electromechanical work room is formed below the liquid storing tank; the liquid storing tank is provided with a projecting cylindrical opening; the shell is provided with a through hole; the diameter of the through hole is greater than that of the opening of the liquid storing tank; the bottom of the shell is provided with a radiating groove; the bottom of the liquid storing tank is provided with a liquid outlet; and one side of the shell is provided with a spray gun. The electric backpack water-series fire extinguisher tank body has the characteristics of scientific structure, novel appearance, reasonable configuration, advanced function, lightness, flexibility, convenience in carrying, comfort for backpacking, easiness in operating, efficient fire extinguishing, economic efficiency, practicability and the like.