NOVELTY - A hydrogen preparing device comprises a sleeve reforming reactor having an inner cavity (10), and a tail gas collecting purifying system (13). A reforming catalyst is provided in the inner cavity. The inner cavity includes an electric stove wire (8) comprising nickel-chromium, or iron-chromium-aluminum alloy. The reforming catalyst is a nickel group catalyst, and/or a composition metal oxide catalyst.    USE - A hydrogen preparing device.    ADVANTAGE - The device provides thermoelectron to catalyst using heating electric stove wire, to dissociate and degrade complex carbon-hydrogen-oxygen molecule in a biological oil, obtaining high hydrogen-producing rate and biological oil at 450-550 degrees C.    DETAILED DESCRIPTION - A hydrogen preparing device comprises a sleeve reforming reactor having a heat preservation layer, an inlet pipeline (16), an output pipeline, a biological oil storing tank, a water vapor generator connected with the inlet pipeline, and a control valve (20); and a tail gas collecting purifying system comprising a water vapor condenser, a carbon dioxide chemical reaction absorber, and a drier connected on the output pipeline. A reforming catalyst is provided in an inner cavity of the sleeve reforming reactor. An outer heating furnace is set on the outer wall of the reactor. The inner cavity includes an electric stove wire connected with an outer connection power supply. The reforming catalyst is filled around and in contact with the surface of the electric stove wire. The re-forming catalyst is a non-noble metal water vapor reforming catalyst particle having a particle diameter of 0.1-0.3 mm. The outer wall of the inlet pipeline has an outer heating device for preheating. The reforming catalyst is a nickel group catalyst, and/or a composition metal oxide catalyst. The electric stove wire is nickel-chromium, or iron-chromium-aluminum alloy.    DESCRIPTION OF DRAWING(S) - The drawing is a sectional view of the hydrogen preparing device.    Electric stove wire (8)    Inner cavity (10)    Tail gas collecting purifying system (13)    Inlet pipeline (16)    Control valve (20)