Abstract: Focusing on the problems like platform displacement and damage of riser that may arise in deepwater drilling under the presence of internal waves, the paper analyzes the regular characteristics of internal waves in the South China Sea and establishes an early warning system based on the impacts of internal waves on the drilling platform, the riser, and the subsea wellhead safety through Doppler acoustic marine speedometer and conductivity bathythermograph. With consideration to field operations, a technical solution for the drilling platform to adress internal waves is developed and suggestions on follow-up research on internal waves in the South China Sea are provided.