The invention discloses a flight vehicle electrical system based on power line broadband carrier wave communication. No specific communication cable is arranged among the various devices of the flight vehicle electrical system based on the power line broadband carrier wave communication, and all of communication signals are transmitted by 28V power supply cables (power lines). The communication bus of the flight vehicle electrical system adopts a shared bus type topological structure, and the communication is realized on an irreplaceable power supply line, and therefore no specific communication cable is required, the wiring difficulties of the flight vehicle and ground are reduced, the flight weight of the flight vehicle is reduced, effective load weight is increased, the reliability of the flight vehicle electrical system is improved, and designing work is mainly divided into hardware design and communication protocol design.