Abstract: In order to make up to the hot rolling and cold rolling process for the lack of processing capacity or high cost of seamless steel tubes for large-caliber thin-wall gas cylinders, the technology of thermal expansion and cold drawing was developed and improved to manufacture the seamless steel tubes. The test results prove that:the cylinder steel tubes manufactured by this technology could meet the requirements of GB 28884-2012, and also meet the agreement requirements of customers in performance, dimension and so on, and they could make up for the lack of such gas steel tubes in the market.