SG1500 portable flue gas analyzer adopts self-developed UV spectrometer and high-temperature reflective gas chamber, through the miniaturization and lightweight design, the high-temperature pretreatment sampling system and UV differential detection device installed into a small portable equipment. It is especially suitable for monitoring low concentration pollutant gases in complex and disturbing compositions in low temperature and high humidity flue gas environments. The instrument has a built-in humidity sensor, which can directly calculate the wet base value to dry base value, to meet the needs of environmental protection monitoring and comparison.