The secondary energy on board has been gradually replaced by electrical power in more electric aircraft， effectively improving the fuel economy， reliability and maintainability of the aircraft， and has become an important direction of the aviation technology. As the core of the secondary energy system on board， the power system plays a key supporting role in the development of more electric aircraft. The innovative development of the power system and related technologies are the necessary basis to realize the improvement and global optimization of the aircraft comprehensive performance. Based on the concepts and characteristics of more electric aircraft， this paper analyzes and compares the electric power system architecture of three typical more electric aircraft， summarizes the key technologies supporting the development of more electric aircraft electric power system， and discusses the development trend of high voltage， direct current and intelligent more electric aircraft electric power system in the future.