The invention belongs to the field of iron and steel production, and in particular relates to large capacity high pressure gas cylinder steel and a production method thereof. The invention aims at solving the technical problems of providing the large capacity high pressure gas cylinder steel and improving the quality and comprehensive mechanical properties of the large capacity high pressure gas cylinder steel. The large capacity high pressure gas cylinder steel provided by the invention comprises the following components in percentage by weight: 0.33-0.38 percent of carbon, 0.15-0.35 percentof silicon, 0.80-0.90 percent of manganese, 1.05-1.2 percent of chromium, 0.20-0.30 percent of molybdenum, 0.02-0.04 percent of aluminum, not more than 0.010 percent of phosphorus, not more than 0.008 percent of sulfur, not more than 0.015 percent of phosphorus and sulfur, not more than 0.2 percent of nickel, not more than 0.15 percent of copper, not more than 0.015 percent of stannum, not more than 0.015 percent of arsenic, not more than 0.0002 percent of hydrogen, not more than 0.007 percent of nitrogen, not more than 0.0020 percent of T[0], and the balance of ferrum. Only through simple quenching and tempering heat treatment, good and stable comprehensive mechanical properties of the steel provided by the invention can be obtained so that the steel can be used for manufacturing large capacity steel cylinders.