Abstract: Ammonium Perfluorooctanoate（APFO） is a hard-to-degrade, bioaccumulative and toxic per-and polyfluoroalkyl substances（PFAS） that poses a serious threat to the environment and biological health. Although mass spectrometry is effective in detecting PFAS, it is expensive. High-performance liquid chromatography（HPLC） method is a lower-cost detection method, but the existing technology has low stability, reproducibility and efficiency.This study successfully established an HPLC method with aqueous perchloric acid and acetonitrile as mobile phases capable of separating and detecting APFO. The study systematically investigated the effects of mobile phase volume ratio and pH on the detection of APFO. The results showed that the best APFO peaks were obtained under the conditions of aqueous perchloric acid∶acetonitrile= 60∶40, pH=3.5. This method consumed less than 15 minutes per sample, and the limit of quantification of the method was 1.01mg/L. This method achieved similar sensitivity to other HPLC methods using simpler operation and less time and cost, and showed good linearity in the concentration range of 2～50 mg/L. The precision and accuracy experiments showed that the relative standard deviation of the method was within 9%, and the spiked recoveries were between 97.35% and 104.80% for actual water samples, which demonstrated anti-interference for determining complex samples. This study showcases the method’s significant potential for efficient and economical detection of high-concentration PFAS in water treatment material development during initial stages.