The invention provides an annular metal gas bottle with the variable wall thickness. The metal gas bottle comprises an upper ring part and a lower ring part, wherein the upper ring part is connected with the lower ring part together in a welding mode so as to obtain an annular inner cavity in the annular metal gas bottle in a defining manner; the top of an outer ring wall of the upper ring part or the lower ring part is provided with a gas charging pipe nozzle in a welding manner, and the gas charging pipe nozzle is communicated to the inner cavity of the annular metal gas bottle; and a welding seam part on the inner ring of the metal gas bottle is provided with a thickening area, and the wall thickness of the part, on which the thickening area, is positioned of the gas bottle is larger than the wall thicknesses of other parts of the metal gas bottle. According to the annular metal gas bottle with the variable wall thickness, provided by the invention, by thickening the wall thickness of an area with relatively large stress on the inner ring of the annular metal gas bottle, the wall thicknesses of the thickening area and the other areas are uniform in transition to ensure that the overall stress of the gas bottle is uniform in distribution when the gas bottle bears internal pressure, so that the strength of each material can be fully exerted, and finally the weight of the gas bottle can be reduced.