The invention discloses an air-liquid combined cooling device for a double-shaft-shoulder friction stir head. An air-logged center hole is formed in an upper shaft shoulder along the axis. Multiple air guide holes perpendicular to the center hole are formed in the bottom of the center hole. An air guide fan is mounted on the top of the center hole. A huge downdraft is generated along with high-speed rotation of the stir head in the welding process, and heat of the center of the stir head is taken away forcibly and is guided out of the air guide holes in the lower portion of the upper shaft shoulder; a hollow cone is mounted below a lower shaft shoulder, the hollow cone comprises a shell, an opening is formed in the bottom of the shell, a thread is arranged on the inner wall of the shell, and both the lower shaft shoulder and the shell are provided with holes; and a water tank is arranged below the shell, and the opening is located in the water tank. According to the air-liquid combined cooling device for the double-shaft-shoulder friction stir head, the manner of combining the air flow and cooling liquid is adopted, non-welding portions of the upper shaft shoulder and the lower shaft shoulder of the friction stir head are cooled, the temperature of the friction stir head is lowered, and the welding temperature field is controlled indirectly.