Abstract: Radioxenon isotopes detection is of great interest for monitoring compliance with the comprehensive nuclear test ban treaty (CTBT), and is of particular importance for the safe operations of nuclear facilities, enviromental radiation survey and nuclear emergency monitoring. Since the daughters of radon including ²¹⁴Bi and ²¹⁴Pb, can affect radioxenon measurement, radon should be removed before xenon measurement. The study was carried out based on the preparative gas chromatography method. In this work, an experimental setup for preparative gas chromatography was firstly established. Utilizing the setup, the xenon prepared performance and the radon decontaminate coefficient were tested separately. The results show that the experimental setup and the method for xenon preparation and radon decontaminating are practical and efficient. The purified xenon volume, the xenon concentration, the xenon recovery and the radon decontaminate coefficient for the prepared sample are more than 11.5 mL (@STP), 80%, 95% and 10⁵, respectively.