Abstract: An offshore floating-type wind power combined semi-submersible platform foundation has at least three stand columns that form an enclosure having a polygonal structure. The adjacent stand columns are connected by an upper support and a lower support. Each stand column is composed of an upper column body and a lower column body that are arranged coaxially. An upper portion of the upper column body is provided with a support block, the upper support rests on the support block. A lower portion of the upper column body is provided with a lower support connecting portion that is connected to the lower support. With the structural form of the offshore floating-type wind power combined semi-submersible platform foundation, the requirements for a manufacturing site and a combination site are greatly reduced, providing the possibility of large-scale offsite construction.