The invention discloses a vertical annular welding tool. The vertical annular welding tool comprises a rotatable platform and a hollow upright column, wherein the hollow upright column is perpendicular to the rotatable platform and sleeves the rotatable platform via a clearance; a gas guiding ring, a conductive ring and a ground wire grounding copper ring sleeve the upright column; a gas circuit, an electric control circuit and a welding ground wire are arranged in a hollow cavity of the upright column; a workpiece positioning mechanism is fixed on the upper portion of the upright column; and a wire feeding machine and a welding gun mechanism are fixed on the rotatable platform. Rotating power is provided by using a speed reducer; circuit transmission is carried out by using the conductive ring; and gas is turned on, turned off and changed over via the gas guiding ring, the welding gun can be adjusted multi-dimensionally in space, namely, the welding gun can be adjusted in the up-down direction and the left-right direction at an angle, annular welding between tubes, annular welding between a tube and a flange and annular welding between a tube and a plane can be performed, the product differentiation switching efficiency and the welding quality are improved, the welding angle and the welding speed can be freely adjusted, annular welding can be performed rotatably without limitation, workpieces do not need to rotate, and the time can be greatly saved. The vertical annular welding tool is suitable for annular welding between the tubes, annular welding between the tube and the flange and annular welding between the tube and the plane, or is suitable for welding an arc.