NOVELTY - Preparation of page silicon fertilizer comprises (i) adding alkali solution to metasilicate, heating to prepare the high-density metasilicate salt solution, and obtaining the active silicic acid solution after acidifying; (ii) adding active silicic acid solution in drops into the alkali solution and stirring for reacting to obtain the high-density alkali silicon dioxide solution sol and (iii) adding an artificial chelating agent or a natural chelating agent into the high-density alkali silicon dioxide sol, stirring for reacting by heating and dialyzing to obtain the page silicon fertilizer.    USE - The silicon dioxide sol: greatly decreases the heavy metal content; and restrains the heavy metal pollution in rice due to low salt content.    ADVANTAGE - The preparation is simple, convenient, economical and short. The fertilizer is highly stable and can be easily stored and maintained.    DETAILED DESCRIPTION - Preparation of page silicon fertilizer comprises (i) adding alkali solution to metasilicate, heating to prepare the high-density metasilicate salt solution, and obtaining the active silicic acid solution of pH 2-4 after acidifying; (ii) adding active silicic acid solution in drops into the alkali solution of density 0.1-5 M, mixing till the pH is 8-11 and stirring for reacting at 30-90 degrees C to obtain the high-density alkali silicon dioxide solution sol and (iii) adding an artificial chelating agent or a natural chelating agent into the high-density alkali silicon dioxide sol, where the adding amount is greater than 120% of the necessary amount for the chelate reaction with the heavy metal, stirring for reacting at 30-90 degrees C by heating and dialyzing (more than 2 times) to obtain the page silicon fertilizer. INDEPENDENT CLAIMS are also included for:    (1) (i) page silicon fertilizer, where the content of each heavy metal of the silicon dioxide sol is less than 0.05 mg/kg, and the content of sodium is less than 120 mg/kg; and    (2) method for using the page silicon fertilizer by thinning the page silicon fertilizer by water for 20-2000 times to obtain the thinned liquor, and spraying 4-400 g thinned liquor / mu yield.