NOVELTY - Preparing ultra-pure gas with a combination of a liquor pump and a raw material gas cylinder comprises paralleling air supply pipes of the raw material gas cylinder and the liquor pump, discharging e.g. argon and supplying gas to an ultra-pure gas decontamination plant, removing impurities e.g. hydrogen and filling into a product gas cylinder, when the pressure of the raw material gas is same as the product gas, stopping the filling process, starting the pump, when the outlet pressure of the pump is higher than the product gas cylinder pressure and supplying gas to the decontamination plant.    USE - The method is useful for preparing ultra-pure gas with the combination of liquor pump and raw material gas cylinder.    ADVANTAGE - The method: is economical; reduces the diffusion of the raw material gas; and maintains a stable production pressure, good gas continuity and stable gas flow velocity.    DETAILED DESCRIPTION - Preparing ultra-pure gas with a combination of a liquor pump and a raw material gas cylinder comprises: paralleling an air supply pipe of the raw material gas cylinder with the air supply pipe of the liquor pump, adjusting the branch valve and a pressure meter on each pipeline, discharging upwards the raw material gas cylinder of argon or nitrogen with a purity content greater than or equal to 99.995% and supplying gas to an ultra-pure gas decontamination plant, catalytically oxidizing the raw material gas by the ultra-pure gas decontamination plant, drying, removing the impurities of hydrogen, carbon monoxide, methane, oxygen, water and carbon dioxide in the raw material gas to produce gas with a purity content of 99.9999% and filling into the product gas cylinder, when the displayed raw material gas pressure is the same as the displayed product gas pressure, stopping the gas filling process and switching off the raw material gas branch valve, starting the liquor pump, when the outlet pressure of the liquor pump is higher than the product gas cylinder pressure, switching on the liquor pump gas filing valve and supplying gas to the ultra-pure gas decontamination plant, filling and installing into the product gas cylinder and completing the process when the product gas cylinder pressure displays more than 135 bar.