The invention relates to a qualitative and quantitative analysis method for coexistence of ammonium ion and N, N-Diethylhydroxyla, belonging to the field of analytical chemistry technology. The methodcomprises the following steps of: preparing a simulative sample; adopting an ion chromatography, loading 2mmol/L of nitric acid eluent with the flux of 1ml/min; keeping the column temperature at a constant temperature of 35 DEG C, keeping the sampling quantity at 20 Mu L and the pressure at 7MPa; arranging the sample to be measured and high-purity water on a sample disc intermittently; starting to record data after the baseline is stable; adopting a retention time comparison method for the qualitative analysis and adopting an external marking method for the quantitative analysis after completing peak; injecting a certain component with certain concentration quantitatively by an automatic sampler and taking the component as the reference standard; detecting the results to obtain the peak area of the component; drawing the peak area-component concentration working curve; subsequently measuring the peak area of the certain component in the sample to be analyzed and querying the corresponding concentration from the quantitative sampling-working curve. The method can qualitatively and quantitatively analyze the ammonium ion and N, N-Diethylhydroxyla simultaneously in short time.