NOVELTY - The method comprises crushing potassium feldspar and inorganic chlorate such as calcium chloride, compounding potassium feldspar, inorganic chlorate and potassium carbonate in a mass ratio of 1:1 to 2:2 to 5, balling ingredients and roasting at a temperature of 800-1200 degrees C for 2-4 hours, obtaining roasted material and producing carbon dioxide, immersing the material in water in a solid to liquid ratio of 1:1-1:3 and at a temperature of 50-100 degrees C for 3-4 hours and filtering, and obtaining the filtrate with potassium chloride and potassium aluminate.    USE - The method is useful for producing potassium fertilizer and aluminum oxide using potassium feldspar.    ADVANTAGE - The method ensures economical and efficient production of the potassium fertilizer and aluminum oxide with high quality thus increasing grain yield and reducing environmental pollution.    DETAILED DESCRIPTION - The method comprises crushing potassium feldspar and inorganic chlorate such as calcium chloride, compounding potassium feldspar, inorganic chlorate and potassium carbonate in a mass ratio of 1:1 to 2:2 to 5, balling ingredients and roasting at a temperature of 800-1200 degrees C for 2-4 hours, obtaining roasted material and producing carbon dioxide, immersing the material in water in a solid to liquid ratio of 1:1-1:3 and at a temperature of 50-100 degrees C for 3-4 hours and filtering, obtaining the filtrate with potassium chloride and potassium aluminate, where the residue is used as a cement material, pouring the filtrate in water and obtaining carbon dioxide, aluminum hydroxide sediment and filtrate with potassium chloride and potassium carbonate, filtering, roasting aluminum hydroxide and obtaining aluminum oxide, adding trihydrated magnesium carbonate into filtrate with potassium chloride and potassium carbonate, aerating carbon dioxide and obtaining the double salt sediment of potassium bicarbonate and trihydrated magnesium carbonate, filtering, evaporating and crystallizing filtrate, where the potassium chloride fertilizer is obtained, adding water and dissolving double salt, where the solid trihydrated magnesium carbonate is obtained after filtering, heating and resolving the obtained potassium bicarbonate solution, and obtaining potassium carbonate solution. The trihydrated magnesium carbonate and the potassium carbonate in filtrate are in a mole ratio of 1:1-1:2.    DESCRIPTION OF DRAWING(S) - The figure shows a flow chart of a method for producing potassium fertilizer and aluminum oxide (Drawing includes non-English language text).