NOVELTY - A sheet-shaped titanium dioxide array film comprises hexagon titanium dioxide sheets. The diameter of sheet is 5-20 mu m and thickness is 10-100 nm.    USE - Sheet-shaped titanium dioxide array film used in solar cells, photocatalysis and air sensors.    ADVANTAGE - The method uses liquid-phase method to prepare the film on FTO conductive glass at low temperature and without any surfactant and template. The operation is simple and cost is low. The property is stable and purity is high.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing the film which comprises:    (A) ultrasonic cleaning conductive glass substrate containing fluorine-doped tin oxide (FTO) using acetone, alcohol and deionized water in order, and drying using nitrogen for future use;    (B) slowly adding titanium source (0.03-0.08 mol/L) in concentrated hydrochloric acid (5-20 mass%), and adding and stirring at same time and preparing reaction solution;    (C) placing cleaned FTO substrate in reaction solution, and obtaining titanium dioxide nano line array obtained by FTO substrate via water heating reaction;    (D) dipping obtained titanium dioxide nano line array in strong base solution, and obtaining sheet titanium acid salt intermediate product via water heating reaction; and    (E) dipping substrate of titanium acid salt intermediate product in the strong base solution, and converting sheet titanium acid salt intermediate product to sheet titanium dioxide array via water heating reaction.    The titanium source of step (B) is metatitanic acid butyl acetate, propylene glycol titanium or titanium tetrachloride. The water heating reaction temperature of step (C) is at 120-200 degrees C. The strong base solution is sodium hydroxide solution (5-15 mol/L), where temperature for water heating reaction is 120-180 degrees C. The acid solution of step (E) is hydrogen nitrate solution or hydrochloric acid solution (0.1-0.5 mol/L), where temperature for water heating reaction is at 100-160 degrees C.