Abstract: A micro-channel structure for a heat exchanger is formed between multiple layers of heat exchange plates arranged in a stacked manner, with a plurality of fin units formed on the heat exchange plate. The fin units are arranged uniformly into a plurality of fin unit groups in the direction perpendicular to a flow direction of fluid, and the fin unit groups are arranged in a staggered manner and spaced from one another by a distance in the flow direction of the fluid. A rear end of the fin unit at the upstream side is arranged in an intermediate position between two adjacent fin units at the downstream side; the fin unit includes at least two fins, with the adjacent fins spaced from each other by a distance; and the fluid channels between the adjacent fin units and between the adjacent fins form the micro-channel structure.