The invention relates to the field of preservation of cultural relics technology, and discloses a preparation method for 
silk fiber used for protecting 
textile cultural relic. The preparation method comprises: 1), adding 
cyclodextrin and o-iodoxy 
potassium benzoate into 
dimethyl sulfoxide to react; filtering the product, adding 
acetone into the filtrate, filtering, dissolving the 
solid in water, 
freeze drying the filtrate after filtering to prepare 
cyclodextrin mono-
aldehyde; 2), dipping the 
silk fiber in water, degumming; 3), adding the 
silk fiber and 
cyclodextrin mono-
aldehyde into dilute 
hydrochloric acid aqueous solution, heating to react; adding 
sodium cyanoborohydride, reacting, removing the silk 
fiber to wash; 4), putting the silk 
fiber into an impregnation liquid, removing and 
drying to prepare the final finished product. The prepared silk 
fiber can purify air, has antibacterial and antiscolic effects, and can be made into bottom liner of the cultural relic, inner packing of the cultural relic, and set lining cloth of cultural relic display case. The 
textile cultural relic can be protected in close distance, and the damage suffered by the cultural relic can be avoided effectively.