The invention discloses a novel self-molding self-insulation building corner column. An infilled wall 9 is built at first. The infilled wall 9 has functions of filling and heat preservation. The infilled wall 9 is a special self-insulation bar-type wall plate or other building material or a self-insulation infilled wall cast on site. Side surfaces of the infilled wall 9 are used as side molds. The side surfaces, a columnar mold plate 5 and a columnar mold plate 8 compose a columnar casting chamber 4. Rebars are put into the columnar casting chamber 4 and concrete is poured into the columnar casting chamber 4 so that a column 4 is obtained. A thermal insulation material 7 blocks a cold bridge at the column 4. The columnar mold plate 5 with a thermal insulation material 10 blocks a local cold bridge on a connection surface between the infilled wall 9 and the column 4. After mold plate installation and concrete casting, dismounting of the columnar mold plate 5 with the thermal insulation material 10 and the columnar mold plate 8 with the thermal insulation material 7 is avoided.