For improvement of technology stability, reliability and economical efficiency of the shipboard AC distribution electric propulsion system, and requirement of system optimization, a design scheme of shipboard common DC bus hybrid-electric propulsion system with variable speed permanent magnet generator as power supply is proposed, and the system configuration, hardware constitution and network architecture are introduced in the scheme to form the overall technology framework of system design. Such key technologies as DC bus voltage control and selective protection of the DC distribution hybrid electric propulsion system are studied and analyzed, power point calculation, power distribution control strategy and selective protection method based on differential protection of the system under different conditions are determined, and finally DC bus voltage droop control method and network voltage control mode under different power supply unit combinations are provided, so as to satisfy the dynamic response, stability and economical efficiency of DC distribution system under different conditions. The results may be helpful reference for development and design of shipboard DC distribution electric propulsion system at home, and applied to development of the DC distribution electric propulsion system of fishing ships and high-end ships.