With the rapid growth of the demand for heat dissipation in electronic devices, polymer-based composites with high thermal conductivity and excellent thermostability play a key role. Building an effective heat conduction path through precise structural regulation of thermally conductive composites is a simple and reliable solution. In this work, the factors affecting the thermal conductivity of plasticized polyvinyl chloride (PPVC)/graphite composites are analyzed from aspects of geometry dimension, carbon content, and structural regulation of graphite. By comparing the oriented and unoriented composites, the orientation of graphite can significantly improve the in-plane thermal conductivity of the composites. The in-plane and through-plane thermal conductivity of oriented PPVC/graphite composites with graphite thickness of 0.12 μm and carbon content of 99.06 % are 4.63 and 1.87 W·m⁻¹·K⁻¹, respectively. The anisotropic composite model filled with oriented two-dimensional filler is modeled and simulated by finite element method, and the experimental results are verified theoretically.