Abstract: The experiment condition recommended by the analysis standard of a big caliber capillary column for analyzing hydrocarbon impurities was optimized with respect to column temperature control, and the analysis accuracy could meet the standard under normal operation condition. The chromatographic run time was reduced from 40 minutes to 20 minutes. The chromatographic result of complete separation of each component of hydrocarbon impurities in high purity propylene was achieved, and the analysis could be completed in one test. The number of chromatographic instruments was reduced from three to one, and the analysis cost was reduced.