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.
