With the continuous exploitation of deep oil and gas resources, the drilling depth keeps increasing, the sensitivity of the dynamic characteristics of the drill string in the downhole is exacerbated, and the impact of the high-temperature environment in the downhole on the dynamic characteristics of the drill string has also become non-negligible. Firstly, the temperature field distribution of ultra-deep wells is initially calculated using the energy conservation equation. Secondly, the influence of high-temperature environments in ultra- deep wells on the physical and dynamic parameters of drill strings is analyzed, and the finite element model for drill string dynamics in ultra-deep wells is improved and solved numerically. Finally, an example is used to compare and analyze the effect of underground high temperatures on the dynamic characteristics of drill strings. The results indicate that high temperatures significantly impact the movement characteristics of the drill string, while exerting minimal influence on dynamic load, particularly dynamic torque.