To provide a compression solidifying device for pressing a cylindrical element from the back face while an exhaust side of a compressed material can be freely compressed in a diameter direction, wherein a pressing force for acting on the cylindrical element from the back face can be simply adjusted for performing a stable driving, by installing a screw extruder equipped with a feed screw for feeding the compressed material in an axial direction inside a cylindrical easing, linking a cylindrical element whose diameter is gradually reduced towards the compressed material feeding direction to an outlet part at the axial direction end of the easing, and dividing the cylindrical element into plural pieces in a circumferential direction.

This device comprises an oil hydraulic cylinder 28 for pressing each constitutional element of a cylindrical element 27 from the back face, and an oil hydraulic unit 18 for controlling the oil hydraulic cylinder 28. Also, the oil hydraulic unit 18 is equipped with a pressure meter for measuring the pressing force of the oil hydraulic cylinder 28, and a pressure control valve for adjusting the pressing force of the oil hydraulic cylinder 28.