<p>The tooth surface contact stress in the zero-backlash roller enveloping precision reducer (ZREPR) is a critical factor governing its transmission accuracy, efficiency, service life and structural strength. However, due to the complex thermal-structural interaction arising from rolling friction between the worm and the rollers, accurately predicting the frictional heat generated during meshing and the consequent thermal deformation remains challenging, resulting in imprecise characterization of thermal stress distribution and hindering effective design optimization. Here, this study calculates the frictional heat power generated at the interface between the outer and internal ring of the roller and the worm tooth surface, as well as the convective heat transfer coefficients based on the rolling contact characteristics. Taking these parameters as the thermal boundary conditions, a thermal-structural coupling model is established for the ZREPR, which enables the accurate analysis of the tooth surface stress to be realized under the temperature-rising conditions. This study shows that the rolling friction between the outer ring of the roller and the gear tooth surface is the main source of thermal power; the temperature of the worm wheel increases with the increase of the worm rotational speed and the worm wheel load; furthermore, the temperature rise of the worm tooth surface significantly affects the magnitude and distribution of the contact stress, which underscores the necessity of considering thermal effects in the design process. This study provides a valuable theoretical foundation for optimizing the performance and durability of the ZREPR.</p>