The invention discloses a liquid nano-catalysis desulfurizer for a new dry process cement kiln and a preparation method thereof. The liquid nano-catalysis desulfurizer, which is prepared from nano cerium oxide, nano thorium oxide, nano titanium oxide, nano nickel oxide, nano calcium oxide, nano calcium carbonate, carbomite, potassium permanganate, sodium bismuthate, AEO9, octyl phenol polyoxyethylene ether, PEG 200, polymaleic acid, fatty acid polyglycol ester, and diethylene glycol; the allowance is water. In the technical scheme, europium oxide, ferric acetylacetonate and polyoxyethylene ether are added. The desulfurization degree of the liquid nano-catalysis desulfurizer is 100%; sulfur dioxide in smoke gas can be discharged to zero.