The invention discloses a material used to prepare high-pressure U-shaped pipes which relates to a high-pressure water supply heater and is characterized by comprising components with the following mass percent: 0.15 percent to 0.27 percent of C, 0.17 percent to 0.50 percent of Si, 0.50 percent to 1.06 percent of Mn, equal to or less than 0.25 percent of Cr, equal to or less than 0.15 percent of Mo, equal to or less than 0.08 percent of V, equal to or less than 0.25 percent of Ni, equal to or less than 0.20 percent of Cu, equal to or less than 0.030 percent of P, equal to or less than 0.030 percent of S, and the rest is Fe. The average yield stress of the U-shaped seamless high-pressure pipe prepared with the material in the tensile test is 340MPa, the average tensile strength is 530MPa and the average extensibility is 36.7 percent, which totally meet the use requirements of the high-pressure water supply heater; therefore, the material has the advantages of low cost and high performance.