The invention discloses a coupling positioning device of a multi-station special-purpose machine tool. The coupling positioning device comprises a workbench panel, a cutterhead guide rail and a workpiece tray guide rail are arranged on the workbench panel, a cutterhead moving rack is arranged on the cutterhead guide rail, a cutterhead is installed on the cutterhead moving rack, a cutter is installed on the cutterhead, a workpiece tray is arranged on the workpiece tray guide rail, a workpiece and a clamping assembly for clamping the workpiece are installed on the workpiece tray, and positioning holes are formed in the cutterhead moving rack and the workpiece tray respectively. A mother plate is arranged below the workbench panel, accurate alignment holes matched with the positioning holes are formed in the mother plate, guide linkage rods are driven by an external drive device to penetrate through the accurate alignment holes of the mother plate and the workbench panel, and then enter the positioning holes of the cutterhead moving rack and the workpiece tray respectively, and therefore accurate positioning of the cutterhead and the workpiece is achieved. According to the coupling positioning device of the multi-station special-purpose machine tool, the workpiece on each station and the corresponding cutter of the multi-station special-purpose machine tool can be directly positioned, and the relative position relation between the workpiece and the corresponding cutter is accurately ensured.