Method for preparing anode active material for lithium secondary battery and lithium secondary battery to which method is applied

The present invention relates to: a method for preparing an anode active material for a secondary battery, the anode active material being capable of preventing oxidation during the preparation of nano-sized silicon particles; an anode active material for a secondary battery, prepared by the method; an anode for a secondary battery, comprising the anode active material for a secondary battery; and a lithium secondary battery.