The invention relates to an analysis method of a nitrate content in purified adipic acid. The method comprises (1) drawing a work curve comprising: respectively adding a nitrate ion standard solution into seven clean and dry reaction containers, dissolving with an ammonia solution; adding urea and a sodium salicylate solution into the mixed solution, dissolving, adding concentrated sulfuric acid, adding water into the solution, adding a sodium hydroxide solution, cooling to a room temperature, diluting with water, measuring an absorbance of each solution with colorimetric wares by using a reagent blank as a reference, and drawing a work curve to obtain a regression equation; and (2) determining samples comprising: dissolving a purified adipic acid sample in the ammonia solution, employing corresponding steps for drawing the work curve, and calculating to obtain a value of the nitric acid content in the purified adipic acid. The method reduces adding amount of the urea and changes the adding amount of the sulfuric acid, a sample adding standard recovery is between 90-110 %, a relative standard deviation is less than 4 %, repeatability and accuracy of the method is good, and a means is fast and timely.