The invention discloses a loading device for a high temperature steam oxidation test. The loading device comprises a tray. The middle of the tray is provided with a first through hole, which penetrates two opposite surfaces of the tray. The periphery of the tray is provided with a protruded first annular step. The periphery of the first through hole is provided with a protruded second annular step. Between the first annular step and the second annular step, an annular positioning groove for accommodating an annular sample is formed. The positioning groove is provided with at least one second through hole. The positioning groove in the tray is used to accommodate an annular sample; the second through hole in the positioning groove is used for passing-through of water steam; in the test, theinner surface and the outer surface of the annular sample are both soaked in same high temperature steam, the accuracy of the test is guaranteed, moreover, the breaking of the annular sample during the oxidation process is avoided, and the failure of the test is prevented.