A deep understanding of air-sea interaction is an important foundation for weather and climate research, and it is also a long-term challenge. This report focuses on the role and dynamic mechanism of air-sea interaction during the South Asian summer monsoon. So far, the simulation results of the Indian summer monsoon are usually weaker than the observations, and the forecasting ability of monsoon precipitation is also very limited, usually less than 5 days. In response to these problems, this report conducts a series of diagnostic analyses on the climate modes, horizontal ocean structure and vertical stratification that affect the South Asian summer monsoon, hoping that the relevant results will help deepen our understanding of the coupled monsoon system. Meanwhile, taking air-sea interaction and the South Asian summer monsoon as examples, this report also hopes to carry out a more general discussion on the research content and objectives of air-sea interaction.