The invention relates to an underground gas injection pipe column used in oil-field development. The underground gas injection pipe column is capable of preventing injected gas from returning and performing reverse circulation without needing to drop and fish a blanking plug, a packer of the underground gas injection pipe column is installed at the position above an oil layer, a releasing tie-back barrel is connected above the packer, and the lower portion of the packer is connected with a gas injection valve. The upper end of an oil pipe column is connected with a wellhead device, the lower end of the oil pipe column is connected with a casing pressure valve and a sealing plug from top to bottom, and the sealing plug is inserted into the releasing tie-back barrel. The casing pressure valve and the gas injection valve are both check valves, the flowing direction of the casing pressure valve is from an oil casing annular space to an oil pipe, and the flowing direction of the gas injection valve is from valve inside to the valve outside. The trouble that the blanking plug is required to be dropped and fished repeatedly in the prior art is solved, and the risk brought by wellhead dismantling due to less knowledge about underground conditions in the prior art is prevented. The installed casing pressure valve not only meets the requirements of well killing, but also meets the requirements that oil casing annular space protecting liquid needs to be replaced periodically.