Chromium has multiple roles in nickel-based alloy and has outstanding contributions to increasing the wear resistance of alloy coating. At the same time, chromium can form a dense oxidation protective film under the action of high-temperature gas, which significantly improves the alloys resistance to high-temperature oxidation and thermal fatigue performance. However, in the case of high chromium content, chromium easily forms harmful phases with titanium, aluminum, molybdenum, and other elements in the alloy and reduces its strength. So, the quasi-determined value of chromium in nickel-base alloy is very important. Nickel base alloy samples are digested by microwave digestion using hydrofluoric acid, hydrochloric acid, and nitric acid. The matrix is matched by inductively coupled plasma atomic emission spectrometry, and the calibration solution is prepared to determine-chromiums net strength in the nickel-base alloys analysis spectrum line to calculate the content. Given the interference of high-content elements such as Ni, Mo, and Fe in nickel-base alloys on the determination of Cr content, 266.602 nm with fewer interference elements and moderate sensitivity was selected as the analytical spectral line; the matrix effect and the interference effect of coexisting elements were systematically investigated. When preparing the calibration solution, the elements with content greater than 5% were matched with the same content. Prepare the low standard calibration solution Kl Crfor the chromium element, prepare the high standard calibration solution Kh Crfor the chromium element, prepare the sample solution KS Cr, and use the ICP-OES spectrometer to determine the net strength of the low standard calibration solution Kl Cr, the sample solution KS Cr, and the high standard calibration solution Kh Cron the analytical spectrum line in turn, and calculate the chromium content according to the formula. The methods accuracy was evaluated using standard reference materials, and the reliability of the method was verified by comparative analysis using the YS/T 539.4-2009 standard. The results showed that the limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.05 and 0.10 μg·mL-1, respectively, and the relative standard deviation (RSD) of the determination result is less than 2.5%. The relative error (RE) of the comparison analysis result between the measured value and the certified value of the standard reference material is less than 2.5%. This method is easy to operate and accurate to detect. It broadens the detection range for the determination of chromium content in nickel-based alloys by ICP-OES. The lower detection limit is reduced from 2.0% to 0.1%, and the upper limit of detection range is increased from 30% to 33.5%. It greatly improves the efficiency and accuracy of the detection of chromium content in nickel-base alloys. It is suitable for determining chromium content in various brands of nickel-base alloys.