The invention discloses a tumor positioning device which comprises a base. A reversing gear box is mounted on the base in a fixed box, a threaded column is mounted on the reversing gear box, a fixed threaded block is mounted at the upper end of the threaded column and connected with a lifting seat through a support, a bed board is mounted at the upper end of the lifting seat, a sliding seat is mounted in the lifting seat, a second sliding seat is arranged at the upper end of a supporting platform, the upper end of a second threaded slider is connected with a moving frame, annular scanning equipment is mounted at the upper end of the moving frame, a third sliding seat and a third threaded slider moving seat are mounted above the bed board, an electric push rod is mounted in the moving seat,and arc-shaped scanning equipment is mounted at the lower end of the electric push rod. The tumor positioning device can realize tumor scanning examination of the head and the body of a patient, andis supportive of dynamic adjustment, thereby being convenient for tumor positioning examination and accurate in tumor positioning.