The invention relates to a preparation method for 
ferric oxide coated 
tin dioxide nanometer polycrystalline microballoons, and belongs to the technical field of preparation of 
new energy materials of inorganic compounds. The 
ferric oxide coated 
tin dioxide nanometer polycrystalline microballoons are prepared by the hydrothermal method with 
cane sugar, 
urea, 
tin tetrachloride and 
ferric trichloride as raw materials. The method comprises the following steps: dissolving tin 
tetrachloride in water, adding 
cane sugar, carrying out stirring for 0.5 hour at 
room temperature, putting the obtained solution into a hydro-thermal vessel with a volume of 45 ml, heating the solution to a temperature of 180 DEG C for a hydro-
thermal reaction for 24 hours, carrying out 
centrifugal separation when the reaction is finished, and carrying out rinsing with considerable deionized water so as to obtain black 
powder; dissolving ferric trichloride and 
urea in a 
mixed solution of 
ethanol and water, adding the black 
powder into the solution, carrying out stirring and ultrasonic treatment, putting the obtained liquid into the hydro-thermal vessel with a volume of 45 ml, and heating the liquid to a temperature of 60 DEG C for a hydro-
thermal reaction for 48 hours; carrying out 
centrifugal separation when the reaction is finished, and carrying out rinsing with considerable deionized water and 
sintering at a temperature of 500 DEG C in air for 4 hours so as to obtain 
red ferric oxide coated 
tin dioxide nanometer polycrystalline microballoons. The invention has the advantages of simple operation, cheap raw materials, 
environmental protection, high yield, etc.