In view of the lack of data and instability of the elevation benchmarks of overseas water transportation projects,we propose to adopt GPS static precision single point positioning technology (PPP) to unify the elevation of the first phase control points under the ITRF framework.And then obtain the monthly average sea level of the proposed project under the ITRF framework,which can be used as the elevation datum of overseas water transportation projects in the pre-research stage.Finally,the reliability and traceability of the proposed method for establishing elevation control networks in overseas remote areas are verified through the practical application of the New Kikori Port in PNG to provide reference for similar overseas water transportation projects.