Abstract: The integrated development and protection of land and sea is an important topic for the sustainable development of the coastal area. To promote the transformation of land and sea division management to land and sea integrated system management, the scientific delimitation of the integrated zoning of coastal watershed and nearshore is an important tool to promote the integrated management of the coastal zone. From the perspective of physical geography, this study plans to construct a method of integrated spatial zoning of coastal watershed and nearshore. First, this study carries out the determination of coastal zone basin boundary range and its internal multi-level threshold watershed division and river network generation through digital hydrological analysis based on DEM data; second, this study establishes the spatial correspondence between watershed zoning, coastline, and nearshore waters based on the boundary on the coastline of main estuaries and bays; finally, on this basis this study divides the coastal zone area into several watershed-nearshore integrated zoning units. Applying this research method to the Guangxi Zhuang Autonomous Region, where the land-sea linkage pattern is being formed, can provide a spatial reference and scientific basis for integrated land-sea management for ecological environmental protection and sustainable utilization of resources in the coastal zone.