The invention relates to a method for preparing high purity silica white by using rice 
husk ash as a 
raw material, belonging to the field of fine 
inorganic chemical technology. The invention is characterized by comprising the following steps: taking the rice 
husk ash and water for washing under constant stirring, separation, 
pickling, leaching, and then undertaking washing till the lavage liquid is neutral and 
drying; taking the dried rice 
husk ash for being mixed and reacted with the 
sodium hydroxide solution, through leaching and washing; collecting filtrate and washing liquid so as to be condensed and obtain water glass; diluting the water glass which is obtained from the condensation and adding 
metal ion chelating agent, and next carrying out 
precipitation reaction after being fully dissolved, then a 
sediment is obtained by 
centrifugal separation; using 
ultrasound-assisted washing treatment, and then undertaking 
centrifugal separation and repeated washing; placing the washed 
sediment into a 
drying oven and then crushing and packaging the 
sediment so as to obtain the silica white product. The invention has simple process flow, easy operation, can improve the purity of the silica white, and is suitable for commercial process; moreover, the heavy 
metal content is less, which can completely replace or is even better than the market silica white product and also eliminates the environmental 
pollution of the rice husk ash.