Abstract: Impressed current cathodic protection system is a common method used to protect the lower plate surface of tank bottom. Due to differences in domestic and foreign ideas in the protection of tank bottom plate, there are some differences between specific practices of cathodic protection. Some common domestic practices may be not applicable to international projects, adversely affecting the implementation and acceptance of projects. In order to avoid such problems, common problems in the design for cathodic protection system of tank bottom plate involved in overseas projects are analyzed through standard control, design calculation, theoretical analysis and other means in accordance with some project instances. With reference to relevant international standards and practices recommended in the NACE cathodic protection certification courses, cathodic protection design for tank bottom plate is discussed in terms of anticorrosion layer of the tank bottom plate, meshed anode layout, reference electrode layout, insulating treatment of the tank bottom plate, anode material selection and other aspects to recommend a reasonable design proposal.