The invention provides a wall-attached clamping seat with a slideway, which is used for positioning and adjusting a concrete wall supporting template. The wall-attached clamping seat with the slidewaycomprises an embedded rod piece, a pedestal, a supporting portion, and a limiting portion. The embedded rod piece is fixed inside a concrete wall body, and the front end of the embedded rod piece extends out of the concrete wall body. The supporting portion is used for supporting the template, the limiting portion limits the template and the abutting portion at the bottom of the template abuts against the concrete wall body. The supporting portion is formed with a first slideway, the limiting portion is formed with a second slideway, the first slideway and the second slideway move up and downrelative to the embedded rod piece, and the tail end of the embedded rod piece is fixed with the limiting portion. According to the invention, the wall-attached clamping seat with the slideway has the advantages that the position of the joint of the template can be regulated through the fastening of a hillside clamp and a wall penetrating screw rod, and the height of the template is regulated through the up-and-down movement of the regulating assembly, so that the outer wall template can be accurately and effectively positioned.