Abstract: A lithotomy position afterloading carbon fiber treatment couch used in image guiding comprises an afterloading treatment couch board, a source applicator fixing bracket, a left and a right leg fixator The left and right leg fixator comprise a mounting board, an axis sleeve and a leg support respectively. On the couch board is provided an adjustable headrest board. At the other end of the couch board is provided with a source applicator fixing bracket. On the adjustable headrest board is provided a resinous headrest and a headrest adjustment panel. The mounting board of the left and right leg fixator is movably connected to two corners of the same side of the couch board respectively. On the mounting board of the left and right leg fixator are provided leg supports respectively and symmetrically. The leg supports are provided with banding tapes. At two sides of the couch board are provided guideways.