A steady-state thermal model of double-row tapered roller bearings (DTRB) with grease lubrication under a combined load is established in this paper. The influence of the internal load distribution on the temperature allotment of bearings in the circumferential, axial, and radial directions is considered. Firstly, the local heat generation of the bearing is calculated based on the kinematic relationship inside the bearing, the internal load distribution, and the rheological properties of the grease. Then, combined with the heat dissipation analysis of the bearing, the three-dimensional steady-state temperature field of the DTRB is obtained. Ultimately, an analysis is conducted to examine how working conditions, including radial load, axial load, and rotational speed, impact the allotment of temperature fields in a DTRB along its circumferential, axial, and radial directions. The theoretical analysis outcome agrees with the experimental test outcome, providing theoretical guidance for the analysis of the bearing’s three-dimensional temperature field.