Extracting rare earth elements from hematite and developing high-value-added products can improve the comprehensive utilization of mineral resources, inject resources into enterprises and promote the development of high and new technology. The content of rare earth oxides in red mud is low (0.001 0 %~0.050%), and there are many matrix elements such as aluminum and iron in red mud. How to eliminate the interference of matrix elements in the determination of rare earth oxides is important. The traditional acid dissolving methods can cause incomplete digestion of some elements, which are difficult to quantify accurately and has a low recovery rate. In contrast, the alkali fusion methods can introduce a large amount of alkali flux and cause serious matrix interferences, also block the atomizer at the same time. Red mud was melted with sodium hydroxide and extracted with hot water. Triethanolamine solution was used to eliminate the matrix interferences of aluminum and iron, EDTA disodium solution was used to complex with calcium, magnesium and other interfering elements, and rare earth hydroxide was retained in the precipitation, precipitation was dissolved into the liquid to be tested by hydrochloric acid. Thus rare earth elements were separated from fluxes and matrix elements. The experiment showed that the standard solution did not need matrix matching, the linear correlation coefficients of the calibration curve were not smaller than 0.999 9, and the detection limits were 0.000 2%~0.001 5%. The relative standard deviations of rare earth oxides in the sample were between 2.5% and 7.2%, recovery rates were between 85.0% and 105.0%; results of inductively coupled plasma mass spectrometry (ICP-MS) were consistent with that of ICP-OES. ICP-OES realized the analysis of rare earth oxides in red mud in the future.