Abstract: Compared to the single-filler system, polymer composites filled by multiple fillers not only enhance the mechanical performance, but also endow them with new functions, thereby exhibiting excellent comprehensive properties. In contrast to the traditional polymer-based shielding materials, multifiller-filled polymer-based shielding composites demonstrate broader nuclear radiation shielding energy levels, better overall performance, and wider application scenarios, making them one of the most popular research directions in polymer-based radiation shielding materials. This article elaborates on the mechanism of gamma-ray and neutron shielding, summarizes the main types of gamma-ray and neutron shielding elements, and reviews the recent research progress in multifiller-filled polymer-based nuclear radiation shielding composites. Subsequently, it identifies the key challenges in existing studies and analyzes major developmental bottlenecks. Finally, prospects were provided for improving filler dispersion, designing optimized filler combinations, and enhancing the overall performance of multifiller-filled polymer-based nuclear radiation shielding systems.