A fin heat exchanger comprises a set of fins and a heat exchange tube alternating with the set of fins. A metal tube is bent multiple times and then folded at least once to form at least two columns of bent tubing, and then the heat exchange tube is inserted as a whole into the set of fins. In the heat exchanger, no damage resulting from a need for welding is caused to the heat exchange tube, thus the integrity of the heat exchange tube is protected; when a heat-exchange fluid flows through an integrated heat exchange tube, no impact damage is caused to the heat exchange tube as a result of a large fluid impact force, and no leaking of the fluid medium is caused by high-temperature fluid flowing into the heat exchange tube; the heat exchange performance of the heat exchange tube is guaranteed, and there is no problem of unevenness of the inside walls between the welded tube connection ends obstructing the flow of the fluid medium, thereby causing the heat exchanger to have low performance.
