Abstract: The content of sulfate radical in nickel cobalt manganese hydroxide(precursor of ternary anode material NCM) was tested by the inductively coupled plasma atomic emission spectrometry(ICP-OES) method. The appropriate test conditions were determined. Each source of uncertainty, arising from the procedure of testing, was analyzed and confirmed, according to the guidelines of the uncertainty in measurement. After each uncertainty component was evaluated, the combined standard uncertainty and the expanded uncertainty of the result were calculated. The results showed that the concentration of in precursor of ternary anode material(NCM) was 2709±88 mg/kg, spiked recovery of the samples was 97.5%-99.9%, the RSD of the method was 2.02%. The method is simple and efficient.