NOVELTY - A pyridine nitric oxide preparing method involves insulating and reacting hydrogen peroxide and carbamide at 0-40 degrees C. The mixture is cooled at -10 to 15 degrees C. The mixture is centrifuged and filtered to obtain carbamide hydrogen peroxide compound, where a mole ratio of the carbamide and the hydrogen peroxide is 1:0.5-3. The resulting product is subjected to addition of raw material, which is pyridine substituted compound (I) in the presence of the esters or nitriles and anhydride and heating at 30-110 degrees C, followed by adding carbamide hydrogen peroxide compound to react by insulating.    USE - Method for preparing pyridine nitric oxide.    ADVANTAGE - The method enables preparing pyridine nitric oxide in a simple, convenient, inexpensive and eco-friendly manner.    DETAILED DESCRIPTION - A pyridine nitric oxide preparing method involves insulating and reacting hydrogen peroxide and carbamide at 0-40 degrees C. The mixture is cooled at -10 to 15 degrees C and stirred for 0.5-3 hours. The mixture is centrifuged and filtered to obtain carbamide hydrogen peroxide compound, where a mole ratio of the carbamide and the hydrogen peroxide is 1:0.5-3. Dosage of stabilizing agent utilized in the method is 0.001-0.1 g in per kilogram of carbamide, and dosage of esters or ethers utilized in the method is 0.5-3.5 ml in per kilogram of carbamide. The resulting product is subjected to addition of raw material, which is pyridine substituted compound of formula (I) in the presence of the esters or nitriles and anhydride and heating at 30-110 degrees C, followed by adding carbamide hydrogen peroxide compound to react by insulating. The obtained product is cooled at 0-50 degrees C and saturation reducing reagent solution is added till the starch potassium iodide test paper does not change to blue color. The resulting product is subjected to adding aqueous alkali solution to adjust the PH of the system to 8-10, followed by centrifuging, extracting and concentrating to obtain the product.    R1-R5=1-3C alkyl, hydroxy, methoxy or ethoxy (all optionally substituted), H, F, Cl, Br or I.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart of a method for preparing pyridine nitric oxide.'(Drawing includes non-English language text)'