Clamp ring type metal sealgas pipe joint

A clamp ring type metal seal gas pipe joint, wherein the clamp ring type metal seal gas pipe joint is connected to one end of a gas pipe, and the clamp ring type metal seal gas pipe joint comprises a fitting joint, a nut, and a clamp ring, wherein axial contact surfaces of the clamp ring and axial contact surfaces of the fitting joint are respectively provided with a convex portion including two first surfaces configured into a convex V shape and a concave portion including two second surfaces configured into a concave V shape, wherein the convex V shape is matched to the concave V shape, wherein the fitting joint and the clamp ring are configured so that an end part of the gas pipe is compressed between the convex portion and the concave portion to shape the end part into a V shape that matches said convex V shape and said concave V shape, and the shaped end part of the gas pipe is in contact with both the two first surfaces and the two second surfaces, when the fitting joint is tightened and the end part of the gas pipe is self-flared to form a sealing part when the fitting joint is tightened.