Based on the shore power project of a new tourist ship wharf in Shenzhen，we analyze the commonly used shore power supply system and shore power demand of passenger terminal，compare and study the current mainstream grid-connected direct current conversion technology and unit type direct current conversion technology according to the characteristics of the internal distribution facilities of the new tourist ship，propose a scheme of using direct current conversion technology to provide shore power for tourist ships，and compare the consumption data of passenger ships using direct current shore power and fuel oil. The results show that the annual emission of exhaust gas can be reduced by about 25，200 t，nitrogen oxide，sulfide，carbon monoxide and other pollutants by about 75 t，and carbon dioxide by about 2，960 t. The direct current shore power plays a good role in protecting the port environment，and produces the significant social benefits for port enterprises.