The invention discloses a limiting plate structure, an upper reactor inner component and a suspension basket component, wherein the upper reactor inner component is used for installing the limiting plate structure, and the suspension basket component is used for providing support for the limiting plate structure. The limiting plate structure comprises a sliding cylinder and a lower end plate fixedon the bottom of the sliding cylinder, and a plurality of through holes are arranged on the lower end plate, the axis of each through hole is parallel to the axis of the sliding cylinder; a guiding device is arranged on the side wall of the sliding cylinder, after the lower end of the upper reactor inner component is embedded into the sliding cylinder from the upper end of the sliding cylinder, the guiding device is used to limit the movement state of the sliding cylinder relative to the upper reactor inner component; and the sliding cylinder only can slide up and down along the axis of the upper reactor inner component. The limiting plate structure can effectively avoid the problem that a fuel assembly is pressed by a coil spring to reduce the structural strength requirement of the fuelassembly.