Abstract: The content of the same element in separate rare polymetallic ore processing samples is different, and the content of each element in the same sample is also different. For example, the content of niobium, tantalum, lithium, and beryllium in tailings and ore is only a few tens to several hundred μg/g, but in the concentrate these elements have contents of several percent to several percent and associated elements such as potassium and sodium in different samples are also quite different. Determination of niobium, tantalum, lithium, and beryllium by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) commonly involves three acid or four acid decomposition of samples. This method was mostly used to determine the lower content of niobium, tantalum, lithium, and beryllium in tailings, ore and some of ore samples, and the same determination system only analyzes one or two elements. The niobium-tantalum polymetallic ore was dissolved with HF-HCl-HNO₃-HClO₃-H₂SO₄ and extracted by 3-4 drops of mixed hydrofluoric acid, 5% sulfuric acid, and 5% hydrogen peroxide, instead of conventional organic acids (tartaric acid, etc) extraction system, which makes it possible that simultaneous ICP-OES determination of niobium, tantalum, lithium, beryllium, potassium, sodium, rubidium, iron, titanium and other elements in different stages of rare metal ore beneficiation test products is possible. The spectral line intensity shows a good linear relationship when the concentration of elements is 0-500 μg/mL. The relative standard deviation is 0.37%-4.77% (n=6). The method has improved the efficiency of the analysis of various elements in the whole process sample and has been applied in the sample analysis of the smelting process.