Abstract: To enhance the operational safety and reliability of traction transformers for shearers, the thermal source mechanism of these transformers was thoroughly analyzed. A multi-physics model of the transformer was established. For the water-cooling solution in the base layer of the transformer housing for shearers, simulations of the temperature rise in the core and high/low-voltage windings were conducted, with the distribution of the transformer's temperature field and fluid field visualized. The results indicate that the core and high/low-voltage winding regions of the shearers' transformers exhibit local maximum temperature points, with the highest temperature rise in the B-phase winding, while the A- and C-phases show lower values. However, due to the rectangular structure of the A- and C-phase windings, temperature variations exist across different orientations, with higher temperatures near the B-phase end. These findings provide a reference for the temperature monitoring design of shearers' transformers.