To the lack of basic surveying and mapping data and incomplete technical system in unfamiliar and complex terrain and hydrological environments for large-scale overseas port and waterway construction projects,a systematic research and practice of surveying and mapping technology is carried out using the terminal and waterway project in Indonesia Tonga Industrial Park(including inland rivers,bays,and marine composite waters)as an example.This project needs to address technical challenges such as the lack of surveying benchmarks in tropical rainforest coverage areas,unknown underwater terrain,complex tidal and current characteristics,and unclear sediment distribution.By innovatively integrating GNSS（global navigation satellite system） static measurement,multibeam depth measurement,side scan sonar,tidal level harmonic analysis,six point tidal current observation,and joint granularity analysis technology,a comprehensive surveying system covering plane and elevation benchmarks,underwater terrain,hydrological dynamics,and sediment characteristics has been constructed.The technical system proposed in this study has overcome the problem of lack of surveying and mapping data in overseas complex waters,and achieved multi element collaborative surveying and mapping in the tropical rainforest bay strait composite area,which can provide a standardized technical paradigm for similar port projects along the “the Belt and Road”,and promote the deepening application of intelligent unmanned surveying and mapping equipment in overseas projects.