The invention discloses a green energy-saving fabricated building wall and a construction method thereof, and relates to the technical field of building walls. According to the green energy-saving type fabricated building wall and the construction method thereof, the green energy-saving type fabricated building wall comprises a side column device, the side column device comprises side columns, the side column device is formed by vertically stacking a plurality of side columns, the side columns are fixedly connected, a first connecting column is fixedly connected to the middle of the right surface of each side column, and a side column groove is formed in the middle of the left rear side of each side column; the side column groove is inwards formed in the center of the side column, a second connecting column is arranged in the side column groove, the end, close to the side column groove, of the second connecting column is inserted into the side column groove, the second connecting column is matched with the side column groove, and the end, close to the side column groove, of the second connecting column is the circle center end and makes contact with the position, located in the center of the side column, of the side column groove. According to the green energy-saving fabricated building wall and the construction method thereof, the stability of the building wall fabricated through the structure is improved.