The utility model discloses a supporting structure of an oversized foundation platform. The foundation structure comprises group piles, a foundation platform, a foundation bottom plate and a top structure column, the bottom plate reinforcing steel bars comprise bottom plate upper iron and bottom plate lower iron; the bottom plate upper iron and the bottom plate lower iron penetrate through the foundation platform; wherein the channel steel supports are arranged in the foundation platform in a full-length mode in the transverse direction and arranged at intervals in the longitudinal direction.Each channel steel bracket comprises a group of bases, a group of upright posts, two cross beams and a group of inclined struts; the cross beam comprises an upper cross beam and a lower cross beam; the base is fixedly connected with the bearing platform lower iron, the bottom plate upper iron is arranged on the upper side of the lower beam and fixedly connected with the lower beam, the bearing platform upper iron is arranged on the upper side of the upper beam and fixedly connected with the upper beam, the top end of the inclined strut is fixedly connected with the bottom of the upper beam, and the bottom end of the inclined strut is fixedly connected with the side surface of the stand column. The utility model can be widely applied to a large bearing platform, and ensures the constructionsafety of bearing platform steel bars and foundation slab steel bars during the construction of the bearing platform.