The invention relates to intraocular nano particle freeze-dried powders, which comprises 
polylactic acid (PLA) or polylactic-co-
glycolic acid (
PLGA) and glucocorticoids. The powders are prepared by the following steps: firstly, dissolving the glucocorticoids in 
acetone to serve as an inner water phase; dissolving the 
biodegradable polymer PAL or 
PLGA in 
methylene dichloride to serve as an 
oil phase; under the ice-bath condition, mixing the two mixtures, and stirring at high speed to form a water-in-
oil type primary 
emulsion; secondly, under the ice-bath condition, dropwise adding 
polyvinyl alcohol (PVA) serving as an outer water phase in the primary 
emulsion to form a water-in-oil-in-water type multiple 
emulsion through the action of ultrasonication; and finally, stirring the water-in-oil-in-water type multiple emulsion in a stink 
cupboard and volatilizing an organic phase under reduced pressure, collecting and washing the sediments after centrifuging the product, removing the dissociative glucocorticoids and PVA by washing with 
distilled water, and then preparing and storing the freeze-dried powders. The intraocular nano particle freeze-dried powders have the characteristics of having large medicament-
loading rate and 
uniform size distribution and capacities of slowly releasing the glucocorticoids, reducing times of repeated medicament administration for the 
vitreous cavity and reducing the generation of ocular complications.