Method for preparing nano-crystal cellulose II by using basic anion-exchange resin

The invention relates to a method for preparing nano-crystal cellulose II by using basic anion-exchange resin. The method comprises steps of: adding fibers and ion exchange resin into a solvent to obtain a suspension; performing agitation, ultrasound or microwave radiation processing to the suspension; then further performing the ultrasonic dispersion processing to filter out the ion exchange resin and obtain a fiber suspension after separation; and finally obtaining the nano-crystal cellulose II through further high-speed centrifugal purification to the fiber suspension. The invention takes basic anion-exchange resin as an alkaline catalyst that can dissociate OH- from the solution, overcomes disadvantages of liquid alkali reaction, can be used repeatedly, has little corrosion to equipment, excellent catalytic activity, wide temperature range for use, can work normally under different pH values, and has the advantages of slight degrade damage to the cellulose and less environmental pollution.