Abstract: The Marxan system conservation planning model is used to identify conservation (development) spatial priority areas, which can provide decision support for the rational development and conservation of biological resources. Based on the environmental conditions of Sichang sea area in Thailand, the annual average sea surface temperature, annual average chlorophyll a concentration, water depth and distance from the port were selected to construct cost indices, and the Marxan model was used to identify aquaculture priority areas and vacancy analysis. The results show that the aquaculture priority areas are distributed in the sea area around Sichang Island body, with the most concentrated in the northeast and southeast side of the sea area. Combining the natural environment of the surrounding sea area and the current situation of marine activities and utilization, the spatial layout of the aquaculture area is proposed to be adjusted to provide scientific reference for the sustainable development and utilization of spatial resources in Sichang sea area.