NOVELTY - Porous submicron sphere having a porous structure formed by titanium dioxide nanoparticles, is claimed, where the titanium dioxide nanoparticles have an aperture of 5-50 nm and a diameter of 10-100 nm; and the submicron sphere has a diameter of 150-1000 nm and Brunauer Emmett Teller (BET) surface area of 80-200 m2/g.    USE - The porous submicron sphere is useful for preparing porous membrane electrode in dye-sensitized solar cell (all claimed).    ADVANTAGE - The porous submicron sphere exhibits high scattering capacity to visible lights and fast electron transmission performance, improves the light dispersing ability and dye absorption ability of the electrode, and enhances the photoelectric conversion efficiency of dye-sensitized solar cell when the cell used in fields of photo catalysis and photovoltaic conversion.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) preparing porous submicron sphere, comprising (1) dissolving tetraisopropyl titanate or titanate ester in ethanol solution containing a small amount of water and potassium chloride at an atmosphere of protective gas; stirring the dissolved mixture, slowly hydrolyzing the mixture to obtain amorphous submicron sphere with dense interior and smooth surface and without crystallization phase and amorphous submicron sphere suspension liquid, centrifuging or vacuum suction filtering the obtained amorphous submicron sphere suspension liquid, collecting the white precipitate, repeatedly washing the precipitate with water and alcohol, removing potassium chloride to obtain amorphous submicron sphere, heat treating the obtained amorphous submicron sphere by: (a) scattering the amorphous submicron sphere in mixed solution of ammoniac water and alcohol in a volume ratio of (2-7):1, adjusting pH value of the mixture to 2, stirring the mixture to obtain sol and heat treating the sol at the temperature of 120-180 degrees C for 10-30 hours to obtain anatase type submicron sphere; (b) scattering the amorphous submicron sphere in nitric acid water solution and then stirring to obtain sol, and heat treating the obtained sol at the temperature of 200-250 degrees C for 20-40 hours to obtain rutile type submicron sphere with less than 0.5 mol/l of nitromethanone; and (c) scattering the amorphous submicron sphere in nitric acid water solution and then stirring to obtain sol, and heat treating the sol at a temperature of 180-220 degrees C for 10-20 hours to obtain compound phase of rutile and anatase type submicron sphere with 0.01-0.5 mole/l of nitromethanone, centrifuging the obtained submicron sphere, removing solvent by vacuum suction filtering, repeatedly washing the filtrate by deionized water and anhydrous alcohol, drying the washed filtrate at a temperature of 60 degrees C, grinding the mixture to obtain white powder product, and directly scattering the powder in solvent including anhydrous alcohol; and    (2) preparing a porous membrane electrode using the porous submicron sphere, comprising scattering a certain amount of porous submicron sphere in mixed solution of alcohol, terpinol and ethyl cellulose according to a mass ratio of 1:(1-8):(1-10), stirring the mixture for 24 hours after the porous submicron sphere is fully scattered, ultrasonically processing the mixture for 2 hours to make porous nanosphere homogeneously scatter in the mixed solution, spinning and then performing vacuum evaporation on the mixture to remove alcohol, obtaining size fitting for screen printing or blade coating or spinning coating, preparing a layer of membrane in homogeneous thickness on conductive glass base by screen printing or blade coating or spinning coating, sintering the membrane at the temperature of 400-500 degrees C for 30 minutes, naturally cooling the product, and forming the porous membrane electrode.