In view of the failure of tubing string by flow-induced nonlinear vibration（FINV）in high-temperature，high-pressure and high-yield（3H）gas wells，the 3D FINV model of tubing string is established by using the element method，energy method and Hamilton variational principle，which takes into account the self-weight changes of wellbore trajectory，wellbore temperature/pressure，and contact/collision of tubing-casing. The Lagrange and cubic Hermite functions are used to discretize the governing equations，and the incremental form of Newmark and Newton-Raphson are used to solve the FINV model of tubing string. According to the parameters of 3H gas wells in the South China Sea and the similarity principle，a flow induced vibration simulation test device for tubing string is designed. The vibration response data of the tubing string is measured and compared with the calculation results of the theoretical model，and the correctness of the vibration model is verified. Meanwhile，the vibration characteristics of the tubing string are analyzed by using well parameters. The results show that the transverse vibration of the upper tubing is obvious，while the vibration of the middle and lower tubing is close to the casing wall for a long time，which leads to the longitudinal and transverse wear of the lower tubing. At the same time，the longitudinal vibration of the tubing is chaotic，and the chaos phenomenon of the middle and lower tubing string is the most obvious. Therefore，the field designers should pay attention to the safety of the lower tubing string.