The invention provides a heat exchanger core for heat exchange of two or more kinds of fluid, and belongs to the technical field of heat exchange design. The heat exchanger core comprises n heat exchange plate sets and is formed by alternately stacking the n heat exchange plate sets. The n heat exchange plate sets bear n kinds of heat exchange fluid. Heat exchange plates comprise cold plates and hot plates. Each cold plate comprises a cold plate base body, a fluid through hole and a heat exchange flow pass which is machined in the cold plate base body through chemical etching, and each hot plate comprises a hot plate base body, a fluid through hole and a heat exchange flow pass which is machined in hot plate base body through chemical etching. Each heat exchange plate set comprises one or more cold plates or hot plates. The heat exchanger core for heat exchange of three or more kinds of fluid has the advantages of being high in cooling efficiency and the like.