The invention discloses a mechanical seal chemical pump and a using method thereof. The mechanical seal chemical pump comprises a mounting base, two fixing bolt plates are fixedly mounted on each of the front surface and the rear surface of the mounting base, a first supporting frame is fixedly mounted at the position, close to one end, of the upper surface of the mounting base, a second supporting frame is fixedly mounted at the position, close to one side of the first supporting frame, of the upper surface of the mounting base, driving motors are fixedly mounted at the upper ends of the first supporting frame and the second supporting frame, and a third supporting frame is fixedly mounted at the side, close to the second supporting frame, of the upper surface of the mounting base. An impeller has the advantages of high heat resistance, chemical corrosion resistance, aging resistance, mildew resistance, ultraviolet radiation resistance, high density, high hardness and small size deformation, the tensile strength of the plastic material is increased, the durability of the impeller is improved, the service life of a chemical pump is prolonged, a pump cover, a first cylinder and a second cylinder are mechanically sealed, and the sealing performance and the suction force of the chemical pump are improved.