The invention belongs to the technical field of tubular rod forming and particularly provides a forming tool of an ultrathin slender elastic tubular rod. The forming tool comprises a bent male mold, a bent female mold and a shaping tool. The bent male mold comprises a male mold body, a male mold roller sliding rail, a male mold roller support and a male mold roller. The male mold roller can move along the male mold roller sliding rail in the horizontal direction, and forming motion integrating moving and rolling is achieved forwards. The bent female mold comprises a female mold body, a female mold roller sliding rail, a female mold roller support and a female mold roller. The female mold roller can move along the female mold roller sliding rail in the horizontal direction, and forming motion integrating moving and rolling is achieved forwards. The shaping tool comprises a shaping mandrel and a shaping mold. A formed alloy strip and the shaping mandrel are fixed through the shaping mold, and thus a shaping mold assembly is formed. Through the forming tool, the tubular rod which is formed by winding an ultrathin-wall metal strip can be obtained, the formed tubular rod has small forming diameter, and the unfolding-folding storage ratio reaches 100 or over.