The maximum transgression during the Holocene warm period has a profound impact on the coastal areas, however, there are few studies on the shape of the maximum transgression in the north of Hainan Island. In this paper, combining with the interpretation of high- resolution DEM data and field drilling verification, the spatial distribution position of the precise maximum transgressive paleocoastline in Holocene in the north of Hainan Island was discovered. The total area of the largest transgression area is about 260 km2, of which about 115 km2 belongs to the current planning and construction scope of Jiangdong New District, accounting for 38% of the planned area of the whole Jiangdong New District. The discovery of the Holocene maximum transgressive paleocoastline in northern Hainan Island not only provides new evidence for understanding the characteristics and laws of Holocene high sea level in the South China Sea, but also provides a background reference for Hainan Free Trade Port (Jiangdong New District) to deal with the problem of sea level rise in the future.