The application provides a cooling water channel for a casting mold. The cooling water channel adopts a sealing structure in which a water channel insert, a sealing cover plate and a metal corrugated sealing ring are matched with each other, wherein a bottom surface of the metal corrugated sealing ring is corrugated or two side walls of the metal corrugated sealing ring are corrugated, and the sealing cover plate is pressed to enable the metal corrugated sealing ring to generate elastic deformation, so that corrugations on the two side walls of the metal corrugated sealing ring and a side wall of the water channel form multi-point contact or the bottom surface of the metal corrugated sealing ring expands to make the side walls of the metal corrugated sealing ring in tight contact with the water channel to achieve a water channel sealing effect.