The invention discloses a coal gas conveyer pipe full-scale test evaluation method. An X80 or above high-steel full-scale welded pipe is adopted to carry out coal gas conveying test, the full-scale welded pipe is obtained through girth joint welding of a pipe segment with the length of 2m through a pipeline construction practical construction butting technology, and two ends of the above steel pipe are soldered and sealed by pipe end high pressure sealing ends; two ends of the pipe are provided with a gas charge/discharge red copper gas guide tube and a pressure detection meter connected with hollow internal thread high pressure joints, the gas inlet end of the gas charge/discharge red copper gas guide tube is connected with a gas busbar, two ends of the pipe are provided with temperature/humidity detection meters, and wireless video monitoring devices are arranged around the temperature/humidity detection meters; and highly pure N2 is adopted to displace air in the welded pipe before gas charge, and CO2, H2 and N2 are successively introduced to the pipe. N2 is adopted to substitute other gas media in coal natural gas to pressurize, so researches of influences of CO2 and H2 coexistence in the practical pressure and pipe stress state of gas medium conveying on the corrosion of the pipe and researches of hydrogen penetration are realized.