The invention discloses a high-purity ultra-fine torispherical 
silicon micro-
powder prepared from natural 
powder quartz ore and a preparation method of the 
silicon micro-
powder. The preparation method comprises the following steps: by taking the cheap natural 
quartz ore as a 
raw material, adding inorganic dilueted acid which exerts the 
grinding aid effect in an ultra-fine 
grinding machine so as to prepare ore 
slurry, and regulating the pH of the ore 
slurry to 2-3; by taking a zirconia ball as a ball-milling medium, 
grinding for 2-4 hours in the ultra-fine grinding 
machine; when the power of which the particle 
diameter is 2mu m reaches 60%-90% in the high-purity ultra-fine 
silicon powder, adding reductant 
sodium hydrosulfite and complexing agent 
oxalic acid, wherein the dosage of the reductant 
sodium hydrosulfite is 1-2% of weight of ore powder, and the dosage of the complexing agent 
oxalic acid is 0.5-1-5% of weight of ore powder; and after continuing to 
grind for a while, washing, filtering and 
drying. An ultrafine 
processing technology and a purification and bleaching technology are simultaneously achieved in the same equipment; and the preparation method has the advantages of simple process, short flow, low cost and obvious purification effect, and is easy to carry out large 
batch production on scale; and the product can be applied to the fields of 
electronics, electricians, optical fibers, lasers, 
aerospace and the like.