A nano freeze dry process of preparation for a cosmetic composition having a bioactive agent for providing an anti-aging effect on a skin, comprising the steps of: placing the cosmetic composition having a bioactive agent into a capsule container； and nano freeze drying the cosmetic composition by: freezing the cosmetic composition in the capsule container at −170° C.； increasing the temperature to −85° C. and allowing sublimation under vacuum condition； then increasing the temperature to 35° C.； and vacuum drying to obtain a final product, wherein a volume of the cosmetic composition remains unchanged after the process, a water content of less than 5% is inside the final, at least 80% of bioactivity of the cosmetic composition is retained, and significant anti-aging effect is observed after a two-day treatment.
