This paper introduces the design of the marine power supply system from berth No.5 to No.9 in the port area. The frequency of the main ships’ power grids at Shekou port is 60 Hz, with two kinds of distribution voltage, i.e. 6.6 kV and 0.44 kV. The power supply system for the shore considers two voltage levels to meet the demands of different vessels. The plan has a high flexibility and a remarkable effect in energy saving and pollution reduction.