The utility model relates to a multidirectional sliding support device for a reactor vessel. The multidirectional sliding support device comprises a support assembly and a sliding seat body assembly,the supporting assembly extends out horizontally and laterally; the sliding seat body assembly is provided with a horizontally-arranged supporting face, and the supporting assembly can be matched withthe sliding seat body assembly in a sliding mode in the horizontal direction along the supporting face so as to release thermal displacement of the container on the horizontal plane and limit the displacement range of the container on the horizontal plane. According to the utility model, the friction pair of the multidirectional sliding support device has multidirectional freedom degree on the horizontal plane; according to the utility model, thermal displacement of the container on the horizontal plane can be released, the displacement range of the container on the horizontal plane is limited, and thermal expansion of the container and thermal expansion and thermal displacement of the superposition system in different directions can be released while the vertical load of the container iseffectively borne. The friction force of the friction pair of the multidirectional sliding supporting device is stable and controllable.