With the rapid development of modern electronics such as AI chips and new-energy batteries, the continuously increasing heat flux density and stringent safety requirements impose severe demands on polymer-based electronic packaging materials. However, conventional polymers inherently exhibit low thermal conductivity, which limits their ability to dissipate heat efficiently. Moreover, the inherently flammability of polymer can induce fire disaster under thermal runaway, short circuit or external ignition. This review provides a comprehensive overview of recent advances in thermally conductive and flame-retardant integrated polymer composites. Emphasis is placed on the structural optimization and spatial distribution of functional fillers, and on how these factors govern thermal conduction and flame retardancy in polymer composites. In particular, the roles of multicomponent hybridization, surface modification, and heterostructure filler design, as well as horizontally aligned, vertically aligned, and three-dimensional continuous filler networks within the polymer matrix, are systematically discussed. Furthermore, based on current understanding of thermal conduction and flame-retardant mechanisms, key challenges and future development directions for integrated thermal conduction and flame retardancy in polymer composites are outlined. This review is expected to provide useful guidance for the rational fabrication of thermally conductive and flame-retardant integrated polymer composites for advanced electronic packaging applications.