With high-power devices moving towards high voltages, currents, and miniaturization in high-power devices, thermal demands become increasingly stringent. Ceramic substrates are extensively utilized in packaging high-power devices due to their superior thermal conductivity and mechanical robustness. This paper comprehensively reviews the preparation methods, performance characteristics, and research advancements of high thermal conductivity ceramics such as Al₂O₃, SiC, AlN, and Si₃N₄, exploring their compositional influences on thermal conductivity. Subsequently, the article provides detailed insights into metallization technologies including direct copper deposition, copper bonding, reactive metal welding, laser reactive metallization, and thick copper printing, highlighting current challenges and limitations. Finally, the paper offers prospects on the future development of diverse ceramic substrates and their metallization processes.