The invention discloses a semi-submersible type construction platform. The semi-submersible type construction platform comprises an upper-layer construction platform, a lower-layer submerged body, at least one supporting column, a connecting channel and at least two water tank adjusting assemblies, wherein the upper-layer construction platform is provided with a working plane for construction equipment to operate; accommodation equipment and a working space for workers to operate are arranged inside the upper-layer construction platform; accommodation equipment and a working space for the workers to operate are arranged inside the lower-layer submerged body; the upper-layer construction platform and the lower-layer submerged body communicate by the connecting channel; a crawling ladder is arranged inside the connecting channel; each water tank adjusting assembly comprises a water tank, a built-in water pump and an external water pump; every two water tanks communicate by a pipeline; an electromagnetic valve is arranged on each pipeline; and the water storage capacity of each water tank is set as follows: the upper-layer construction platform is positioned above the water surface, and the lower-layer submerged body is positioned below the water surface. The semi-submersible type construction platform can realize all-weather operation under middle-long period wave conditions and is free of influence from water depth and geological conditions, so that the working efficiency of overwater operation is greatly improved.