An apparatus and method for automatically loading drums into a drum container, in which, when the drums filled with radioactive waste are loaded into the drum container, the drums are fed to a designated position, and placed at a fixed position, reducing loading time and manpower as well as minimizing radiation exposure risk associated with radioactive waste treatment. The apparatus includes a drum feeder having conveyor modules transferring the drums and a turntable rotating a drum transferred to an orientation where the drum can be gripped, for sequentially loading the drums, a support frame on which a lid of the drum container is placed when the drums are being loaded, and a crane that grips and transfers the drum or the drum container lid.