With the construction of “the Belt and Road”，the coastal areas of West Africa，Mediterranean and Indian Ocean have obvious long-period wave components due to their specific natural conditions，which have a serious impact on port engineering construction. The example of a port in Africa in this paper has the characteristics of long wave period and large coastal sediment discharge，and long period wave and large sediment discharge are easy to cause problems such as poor mooring stability conditions in the port，heavy sediment deposition，and high construction risks of offshore ships. After studying the general layout scheme，we decide to adopt the layout scheme of excavated-in harbor basin，and verify the scheme by the research methods of wave-sediment mathematical model and physical model test.The results show that the excavated-in harbor basin scheme can better solve the above problems.