A novel thin-wall steel tube constraint reinforced concrete split column comprises four thin-wall steel tube constraint reinforced concrete columns. Contact portions of the tops of the thin-wall steel tube constraint reinforced concrete columns are welded through end welding joints. The thin-wall steel tube constraint reinforced concrete columns comprise longitudinal bars, thin-wall steel tubes, concrete and hoops. The longitudinal bars and the hoops are arranged in the thin-wall steel tubes. The longitudinal bars are arranged at four corners of the hoops. The concrete is poured into the thin-wall steel tubes. The novel thin-wall steel tube constraint reinforced concrete split column has the advantages that advantages of conventional split columns are maintained, and the characteristics of the thin-wall steel tube constraint reinforced concrete columns, such as easiness in manufacture and separation and high shear-resisting performance, are utilized fully to form the novel thin-wall steel tube constraint reinforced concrete split column; the concrete is poured into the steel tubes, formworks are not needed, prefabrication in factories can be realized, construction process is simplified greatly, and construction period is shortened.