Abstract: Using the software MARC/AutoForge 3.1, a three-dimensional thermo-mechanical coupled elasto-plastic Finite Element Method (FEM) was used for the simulation of a two-pass tube tension-reducing process of 33Mn2V steel for oil well tubes. The simulated results intuitionally visualize the metal flow and dynamic evolution of strain, stress and temperature, especially inside the work-piece, and show that their non-uniform spatial distributions on the longitudinal and transverse sections are a distinct characteristic of the tube tension-reducing process.