Method for preparing high-frequency transmission line with longitudinal cladding structure and high-frequency transmission line

The invention discloses a preparation method of a high-frequency transmission line with a longitudinal cladding structure and a high-frequency transmission line. The high-frequency transmission line comprises two insulating core wires, a shielding composite cladding, two ground wires and an outer polyester cladding tape, wherein the two insulating core wires are parallel to each other, and the outer side walls of the two insulating core wires are closely adjacent to each other; The shielding composite jacket is wrapped outside the two insulating core wires, the inner side wall of the shieldingcomposite jacket is closely adjacent to the outer side wall of the two insulating core wires, one side edge of the shielding composite jacket is closely attached to the other side edge of the shielding composite jacket, and the shielding composite jacket has mutual overlapping parts; The outer side walls of the two ground wires are respectively in close proximity to the outer side walls of the shielding composite jacket,