The invention relates to a cavity subdivided type offshore infrastructure and a construction method thereof and aims to provide the cavity subdivided type offshore infrastructure which is simple in structure, convenient to construct and low in cost and the construction method thereof so that horizontal displacement can be reduced. According to the technical scheme, the cavity subdivided type offshore infrastructure is characterized in that the cavity subdivided type offshore infrastructure comprises a steel tube foundation pile and a cavity structure mounted on the steel tube foundation pile in a sleeving mode; the cavity structure is provided with an inner subdivision wall, an outer subdivision wall and partition subdivision walls; the inner subdivision wall is in a round tube shape, the inner wall of the inner subdivision wall is matched with the outer diameter of the steel tube foundation pile, and a gap is reserved between the inner subdivision wall and the steel tube foundation pile; the inner subdivision wall is sleeved with the outer subdivision wall coaxially; and the inner subdivision wall and the outer subdivision wall are connected through the multiple evenly distributed partition subdivision walls between the inner subdivision wall and the outer subdivision wall. The cavity subdivided type offshore infrastructure is suitable for infrastructures of the industries of offshore wind power, offshore platforms and port water transport and belongs to the technical fields of foundation infrastructures and construction.