This paper presents a simple and efficient extended finite element method (XFEM) approach to simulate three-dimensional crack geometry under thermo-mechanical loading conditions. In this proposed approach, thermo-mechanical problem decoupled and get solved for thermal and mechanical loading conditions separately. In-post processing phase, domain based interaction integral has been employed to get individual mode of stress intensity factors (SIFs) for thermal as well as mechanical loading. Further, super-position concept has been utilized to get effective SIFs for equivalent thermo-mechanical loading environment. In XFEM, geometric discontinuities such as cracks, inclusions and holes are not considered a part of finite element mesh or domain. These geometric discontinuities are modelled by adding enrichment functions in the displacement approximation of FEA through partition of unity (PU) framework. Primarily two enrichment functions are required to capture crack discontinuity in XFEM: first one is strong discontinuity across the crack surface while the second one is asymptotic at the crack front. In addition, level set functions are used to accurately model the crack geometry. An embedded planar shape crack in 3-D geometry is simulated to reveal the sturdiness and versatility of the proposed XFEM approach. A generalized in-house MATLAB code has been developed to simulate thermo-mechanical crack problems. From these simulations, it can be concluded that the XFEM can be easily and accurately used to simulate the thermo-mechanical crack problems. © 2017 Elsevier Ltd.