With the fast development of the natural gas industry, volcanic gas reservoirs have been paid an increasing attention. Many deep gas wells in volcanic reservoirs have special characteristics, such as high temperature, high pressure and high level of CO2 with strong corrosion effect, which brings great challenge to the safety of the tubing. Therefore, the mechanical analysis of tubing in deep gas wells in volcanic reservoirs is helpful to design the strings, optimize operation parameters and predict service life. In this paper, based on the buckling analysis, a mechanical model of tubing is established and solved by stepwise iterative algorithm. Physical properties of tubular strings and fluid are taken into consideration in new model, as well as the pitting corrosion of CO2. A program also developed for practical purposes. The results can be applied for the safety assessment and life prediction of the tubing in deep gas wells in volcanic reservoirs.