Interference and confusion between electromagnetic signals have become the primary challenge in the era of 5G wireless communication, and the development of high-performance electromagnetic shielding materials that effectively shield high and low frequency electromagnetic interference has become a hot topic in current research. In the future, electromagnetic shielding materials will develop towards ultra-thin, flexible, lightweight, broadband efficient absorption, high temperature resistance, and good mechanical properties. Polyimide (PI) is used as the matrix material of many advanced electromagnetic shielding composites because of its good mechanical properties, good thermal stability, light weight, and flexibility. Therefore, this paper introduces the shielding mechanism of PI electromagnetic shielding materials and summarizes the influencing factors and research progress of their shielding performance. Finally, the future development trend of high-performance PI electromagnetic shielding materials is described to provide reference for the subsequent research of PI electromagnetic shielding materials.