Unmanned early warning aircraft system represents the development trend of the next generation of early warning aircraft. With its unique performance advantages, it has attracted more and more attention all over the world. Compared with the manned early warning aircraft radar system, the unmanned early warning aircraft radar system is subject to the aerodynamic shape, working environment and resource supply of the platform, and faces many special technical problems. This paper analyzes the advantages and characteristics of UAV, analyzes the current technical problems faced by UAV radar system from the perspective of engineering design, expounds the system lightweight design, array configuration design, high-efficiency environmental control design and broadband high-speed and reliable data link transmission technology, and gives the preliminary implementation path and solution of its key technologies.