Abstract: The miniaturization and high-power development of electronic devices pose critical challenges for the thermal management of packaging materials, where conventional resin systems fail to meet next-generation requirements. Composite materials incorporating high-thermal-conductivity fillers offer a viable pathway to enhance resin performance, with boron nitride (BN) emerging as a promising filler for epoxy resin (EP) matrices due to its exceptional thermal conductivity, electrical insulation, and chemical stability. This review first systematically analyzes three thermal conduction mechanisms in BN/EP composites. Subsequently, it examines covalent and non-covalent modification strategies for BN fillers and their mechanistic roles in enhancing interfacial compatibility and thermal transfer efficiency. Furthermore, methodologies and technical features for constructing three-dimensional (3D) BN thermal networks are elaborated. Finally, the future development direction of BN/EP composite materials was prospected, aiming to provide theoretical guidance and technical references for the design and development of high-performance thermal conductive epoxy resin-based composite materials.