In the design process of Djibouti LNG plant site,due to the lack of available hydrological data and the late start and short duration of field observation activities (only one year),it is unable to meet the demand of calculation of design wave elements in multi-year return period,which brings great difficulties to the follow-up work.Driven by the CCMP wind data,based on the wave action balance equation,a large-scale wave mathematical model of the Indian Ocean,a nested mid-range model of the Gulf of Aden and a small-scale model of the project area are established.On the basis of the field measurement data,the model is verified and compared with the Jason satellite orbit data in the same period,and the model verification results are good.On this basis,the hourly wave process from 1988 to 2017 is calculated,and the annual extreme wave sequence at deep water is constructed.The P-III type distribution function is applied to estimate the wave extreme values in the project deep area at different return period,which is combined with different hydraulic conditions to calculate the design wave parameters in the project area.