Abstract：China is rich in salt lake resources. The determination of fluorine,chloride,nitrate and sulfate ions in brine is of great significance for the development of salt lake resources. When using ion chromatography to analyze the anions in brine，the high chloride ion concentration will affect the determination of fluoride, nitrate and sulfate ions. In this study, silver oxide was used as precipitant to effectively remove the high concentration of chloride ions，and the pH of the solution was adjusted by the cation exchange resin, which has improved the measurement accuracy of fluoride, nitrate and sulfate ions. The recovery of the three ions was 913%～108%. The method is simple to operate, suitable for the analysis of anions in brine.