By incorporating two different fracture mechanisms and salient unilateral effects in rock materials, we propose a thermomechanical phase-field model to capture thermally induced fracture and shear heating in the process of rock failure. The heat conduction equation is derived, from which the plastic dissipation is treated as a heat source. We then ascertain the effect of the non-associated plastic flow on frictional dissipation and show how it improves the predictive capability of the proposed model. Taking advantage of the multiscale analysis, we propose a phase-field-dependent thermal conductivity with considering the unilateral effect of fracture. After proposing a robust algorithm for solving involved three-field coupling and damage-plasticity coupling problems, we present three numerical examples to illustrate the abilities of our proposed model in capturing various thermo-mechanically coupled behaviors.