Design method and system of offshore wind plant

The invention relates to the field of offshore wind power energy engineering specifications, and discloses a design method and system of an offshore wind plant. The method comprises the following steps: determining an engineering sea area of a to-be-built wind power plant; calculating the runoff source solid particulate matter content in the engineering sea area within the specified duration; if the calculated solid particulate matter content of the runoff source is smaller than a preset threshold value, or the calculated solid particulate matter content of the runoff source is larger than or equal to the preset threshold value but the specified organisms in the engineering sea area cannot be extinguished in the deposition state, the wind power plant to be built adopts a land area extension type structure, and otherwise, the wind power plant to be built adopts an offshore type structure. The implementation mode of the application gives consideration to the construction of the wind power plant and the protecti