The invention relates to a welded connection structure of a bellows and joints. The welded connection structure comprises the bellows and the calipers flange joints, wherein inserted straight pipes are respectively welded at the two end parts of the bellows; one ends of the inserted straight pipes are provided with welding bosses used for being connected with one end part of the bellows, and the other ends of the inserted straight pipes are connected with the calipers flange joints; arc-shaped grooves are arranged in positions in the surfaces of the welding bosses, which are close to the connecting ends of the bellows; butting bosses butted with the end parts of the inserted straight pipes are arranged on the inner walls of the calipers flange joints; and inward concaved ear grooves are arranged in bent positions in the inner walls of the butting bosses and the calipers flange joints. By adopting the welded connection structure, the welding firmness is increased; besides, the arc-shaped grooves are arranged in the welding bosses, so an original welding rod is evenly and uniformly welded and melted during welding, the tension contractility of the bellows is increased and the quality yield is improved; and the welded connection structure has the advantages of convenience and rapidity in mounting, simpleness in structure, safety, reliability, low maintenance cost, steadiness in connection, high sealing performance and long service life, and is suitable for volume production.