The invention provides a three-stand-column floating platform. The three-stand-column floating platform comprises a floating box, three stand columns, a truss structure, an upper deck and a lower deck, wherein the floating box is constructed in the mode that the cross section is triangular in general, and a through hole penetrating through in the longitudinal direction is formed in the middle of the floating box; the three stand columns are in parallel and arranged on the outer side of the floating box at equal intervals, the lower portions of the three stand columns are connected with the floating box; the truss structure is arranged on the three stand columns, and is a double-layer structure in the mode that an upper truss and a lower truss are jointed through connecting rods, projection of the lower truss in the horizontal direction is triangular in general, and the lower truss is connected with the upper ends of the stand columns; the platform device is arranged on the upper deck and the lower deck. According to the three-stand-column floating platform of the embodiment, the special truss structure is adopted, and on the premise that the whole strength requirement of the three-stand-column floating platform is met, the weight of the whole platform structure is greatly decreased, arrangement of the device is considered at the same time, and the strength and the use efficiency of the deck structure can be quite effectively improved.