The connecting rod small-end bearing system is one of engine's rotating friction pairs under the most severe condition. Significant deformation, high temperature, and the coupling action of multi-bearing tribology and multi-body dynamics make the simulation challenging. This study develops a new tribo-dynamics model considering deformation and thermal effects for the small-end bearing system. A full-scale engine test is conducted, and the predicted severe wear position is consistent with the experimental one. Results show the axial uneven wear and temperature rise happens in the bearing lower surface after considering elastic deformation and thermal effects. The piston pin is decelerated to stop nearly and then accelerated by the friction torque during compression and work strokes that differs from the simplified rigid model.