A method for preparing a tea leaf extract is used for preparing the tea leaf extract with improved anti-oxidation activity. The method includes smoldering a rice husk sample at 200-400° C. in a low oxygen environment for 2-4 hours, followed by burning at 400-600° C. in an atmospheric environment for 2-4 hours to obtain a rice husk silica. An oxygen concentration in the low oxygen environment is below 5%. The rice husk silica is dissolved in an alkaline solution to obtain a rice husk silica solution. A tea leaf sample is then extracted by the rice husk silica solution.
