Abstract: With the rise of 5G networks, electromagnetic radiation and interference issues are becoming increasingly prominent, so the development of effective electromagnetic shielding materials is particularly urgent. Compared with the high cost, high density, difficult processing, easy corrosion and many other limitations of traditional metal-based electromagnetic shielding materials, polymer-based electromagnetic shielding composites have attracted much attention due to their excellent properties such as low density, corrosion resistance and easy processing. The construction of heterogeneous structures such as isolation structure, porous structure and layered structure can induce the orientation distribution of conductive fillers, so that polymer-based electromagnetic shielding composites can obtain excellent conductivity at low filler content, thereby improving their shielding performance. Based on this, this paper reviews the current research progress of polymer-based electromagnetic shielding composites with heterogeneous structures, focusing on the construction strategy and preparation technology of heterogeneous structures and their influence on electromagnetic shielding performance. Finally, prospects for the future development of polymer-based electromagnetic shielding composites with heterogeneous structures are proposed. This work has guiding significance for improving the performance of polymer-based electromagnetic shielding composites and the development of their applications in communications, smart wearables, aerospace and other fields.