NOVELTY - Modifying sodium borate comprises: (i) mixing sodium tetraborate and boric acid, tiling on a roasting kiln car and introducing in a roasting kiln; (ii) warming and heating the material to melt and dehydrate, removing out of the kiln, cooling and grinding to obtain the modified product; or (ii a) warming and heating, reacting, warming to remove out of the kiln after complete dehydration, cooling and grinding to obtain the modified product; or (ii b) warming and heating, warming and reacting to remove out of the kiln after polymerization, cooling and grinding to obtain the modified product.    USE - The method is useful for modifying sodium borate.    ADVANTAGE - The method: is simple, prepares tetraborate pentahydrate, borax pentahydrate and anhydrous borax by just controlling distribution and temperature on same or different equipment; saves energy; and is environment-friendly. The modified sodium tetraborate pentahydrate product has good and high water solubility and thus prevents boron from getting solidified by ion in soil and can be easily absorbed by the crops.    DETAILED DESCRIPTION - Modifying sodium borate comprises: (i) mixing sodium tetraborate and boric acid in a mass ratio 4:0-1.05, tiling on a roasting kiln car with 8-160 mm of tiling thinness and introducing in a roasting kiln; (ii) warming and heating the material to 70-100 degrees C to melt and dehydrate, continuing to react for 50-80 minutes, removing out of the kiln, cooling and grinding to obtain the modified sodium tetraborate pentahydrate product; or (ii a) warming and heating the material to 70-140 degrees C to melt and dehydrate the material, reacting for 20-30 minutes at 70-140 degrees C, warming to 410-450 degrees C to remove out of the kiln after complete dehydration, cooling and grinding to obtain the modified sodium tetraborate anhydrous product; or (ii b) warming and heating the material to 70-140 degrees C to melt and dehydrate the material, reacting for 20-30 minutes at 70-140 degrees C, warming to 310-360 degrees C and reacting for 20-40 minutes at 310-360 degrees C to remove out of the kiln after polymerization, cooling and grinding to obtain the modified tetraborate pentahydrate product.