In recent years, scholars have conducted extensive research on air precoolers, which are used for pre-cooled combined cycle engines for hypersonic aircraft. These precoolers are generally composed of multiple sets of micro-tube bundles, but they have problems such as large flow-induced vibration and high processing requirements. Therefore, it is necessary to redesign the heat exchange core of the precooler and carry out further research on flow heat exchange. This article analyzes the demand for modification based on biomimetic fractals, sorts out the application of honeycomb-like fractals, tree-like fractals, and mixed structures on biological surfaces, which enhance heat exchange in new pre-cooling cores. Additionally, biomimetic concave-convex surface structures and hydrophobic structures are applied to reduce surface flow resistance and suppress frosting. At the same time, three design examples of “cylindrical” biomimetic pre-cooling heat exchange cores are given, which can be applied to the aerospace field. Finally, the article looks forward to the development prospects of combining biomimetic microchannel heat exchange structures with precooler heat exchange core design.