This paper presents a new and rigorous method for simulating thermo-elasto-plastic responses of soil during the cylindrical cavity expansion process under undrained conditions. The soil is modeled by a modified nonisothermal unified hardening model, which can properly consider thermal effects on mechanical responses, thermally induced excess pore water pressure as well as the overconsolidation characteristics. The temperaturedependent governing equations are derived by combining equilibrium equations and constitutive relations. New solution algorithms are developed to solve governing equations and update temperature -related parameters during the expansion process. Two typical scenarios, one is cavity expansion under different temperatures and another is temperature variation after expansion, are simulated. The proposed computational approach is validated through comparisons with results obtained from Abaqus numerical simulations, non -isothermal analyses, and experimental data. As demonstrated by extensive parametric studies, the proposed computational approach can reasonably capture the influence of temperature on cavity expansion, which can be further applied, modified, and developed for various industrial and geophysical problems involving thermoplastic soils.