TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The reaction medium comprises water and oxidizing-reducing anion group. The oxidizing-reducing anion group further comprises ionic compound of iodine and iodate on a molar ratio of 0.5-1:1, where the molar concentration of the oxidizing-reducing anion group in the aqueous solution is 0.1-10 %. The ionic compound of iodine is at least one of sodium iodide and potassium iodide and iodate is at least one of sodium iodate and potassium iodate. The gas separating film is located at the inlet of the circulating pipe for blocking the products of the light-catalyzing reaction of hydrogen and oxygen to pass; the gas separation film is located at the upper side of the reaction medium for blocking water; the gas separation film is the Nafion film and the gas separation film is any one of polyamide film or polyimide film. The light switching-catalytic hydrogen preparation composite material comprises a transparent infrared light switching core layer and a light-catalyzing hydrogen preparation film layer. The light switching-catalytic oxygen preparation composite material comprises a transparent infrared light switching core layer and a light-catalyzing oxygen preparation film layer. The transparent infrared light switching core layer is made of a transparent infrared light switching glass material or a transparent infrared light switching glass film composite material. The light-catalyzing hydrogen preparation film layer is made of any one of composite modified tantalum oxynitride, tantalum nitride or bismuth vanadium oxide from the noble metal or modified titanium dioxide. The light-catalyzing oxygen preparation film layer is made of composite modified tungsten oxide from the noble metal and the noble metal is at least one of Platinum and iridium. The transparent infrared light switching glass material is any one of silicate glass, phosphate glass or oxyfluoride glass mixed with infrared conversion rare earth functional ion. The infrared conversion rare earth functional ion is at least one of sensitization ion Ytterbium (3+), light emitting ion Thulium (3+) and erbium (3+). The mixing molar amount of the sensitization ion Ytterbium (3+) are 2-30 % of the total molar amount of the oxide in the transparent infrared light switching glass material and the molar ratio of Ytterbium (3+) to (Thulium (3+) and/or erbium (3+)) is 0.1-5:10. The transparent infrared light switching glass film composite material comprises a transparent glass base and a transparent infrared light switching film on a thickness of 0.01-1 mm. The transparent glass base is any one of quartz glass, phosphate glass, magnesium aluminum silicate and borosilicate glass. The transparent infrared light switching film comprises silicate or phosphate base and nano crystal sodium yttrium fluoride to Ytterbium (3+), (Thulium (3+), erbium (3+)); lithium yttrium fluoride to Ytterbium (3+), (Thulium (3+), erbium (3+)); Yttrium aluminum garnet to Ytterbium (3+) and (Thulium (3+), erbium (3+)), and the content of the nano crystal is 5-30 % of the weight of the silicate or phosphate base for the transparent infrared light switching film.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The light switching-catalytic hydrogen preparation composite material and the light switching-catalytic oxygen preparation composite material are fibrous, bar-shaped or tubular in shape. The circulating medium controlling unit comprises a circulating pipe, a circulating pump and a medium concentration controller. The circulating medium controlling unit communicates with the light-catalyzing hydrogen preparation reaction unit and the light-catalyzing oxygen preparation reaction unit to perform circulating exchange and concentration control of the oxidizing-reducing medium. The circulating pipe is connected with the lower inlet of the reactor tank B from the upper outlet of the reactor tank A. The circulating pipe is connected with the upper inlet of the reactor tank B from the lower outlet of the reactor tank A. The medium concentration controller further comprises a water tank, a flow guide pipe and a flow amount controller and communicates with the circulating pipe through the flow guide pipe.