The invention discloses a double-reverse-U-shaped boiler, which is formed by two half-capacity reverse U-shaped boilers through being arranged in a face-to-face way. Hearths are arranged in the centers of the boilers, the two sides of the hearths are respectively provided with a left flue and a right flue, a high-temperature part of a primary re-heater and a high-temperature part of a secondary re-heater are respectively arranged in radiation heated regions at the left side and the right side of the top of the hearths, and a low-temperature part of the primary re-heater and the low-temperature part of the secondary re-heater are respectively arranged in the left side flue and the right side flue. The high-temperature part and the low-temperature part of the primary re-heater or the secondary re-heater can be arranged at the same side of the boilers, or can be arranged in a crossed way at the two sides of the boilers.