Abstract: Several models of specific activity of gaseous tritium were compared and analyzed. Combined with the environmental conditions of a nuclear power plant in coastal China, the radiation dose of CFETR to the public surrounding the site after gaseous tritium emission during normal operation and overhaul years was evaluated and calculated. The evaluation model of gaseous tritium recommended in TRS472 takes into account the transfer of gaseous tritium between plants and animals, and distinguishes the transfer of organic tritium and inorganic tritium in plants and animals. However, the gaseous tritium evaluation model recommended in the IAEA report No.19 and the Guide RG 1.109 only considers the balance of tritium concentration in the environment and human body. The calculation results are too conservative. The 30-year model is similar to the TRS472 report, with a simplified treatment of the transfer pathways in the model. The maximum personal effective dose of gaseous tritium emitted from CFETR to the surrounding public in normal operating years is 3.38～14.31 μSv/a, and in overhauling years it is 15.05～63.61 μSv/a. There is still a margin relative tothe public radiation dose constraint value（0.25 mSv/a） of nuclear power plant stipulated in China’s national standard GB 6249—2011. But it takes a large share, it is necessary to pay attention to the radiation environmental impact of gaseous tritium emission of CFETR.