<p>Due to the excellent wear resistance, corrosion resistance and high temperature stability characteristics of ceramic bearing, it is widely used in aerospace, automotive and high-precision machinery and other fields. However, ceramic bearings are affected by many factors in production application. The nonlinear dynamic behavior of the ceramic bearing-rotor system is primarily attributed to cage pocket wear and thermal expansion. Thermal expansion induces variations in the relative positions of bearing components, which, in turn, exacerbate the nonlinear dynamic response associated with wear. In this study, a nonlinear dynamic model with ten degrees of freedom is developed using the lumped-mass method, accompanied by dimensionless processing, to analyze the effects of cage wear on the dynamic characteristics of the system under thermal expansion conditions. The model incorporates the additional position angle resulting from both thermal expansion and cage pocket wear, while also accounting for the interaction forces between the cage and other bearing components. The nonlinear vibrations are systematically investigated through numerical simulations, employing analytical tools such as bifurcation diagrams, phase trajectories, Poincaré sections, and vibration response diagrams to elucidate the system’s dynamic behavior. Finally, in the experimental part, the vibration results of experiment and simulation are compared. The results show that the amplitude of the system is enlarged under the influence of thermal expansion and cage wear. Meanwhile, the vibration signal shows obvious periodicity. Then, the energy of vibration is gradually concentrated in the low-frequency vibration. In addition, the spectrogram makes it easier to identify frequency components of the cage, such as <i>nf</i>_<i>c</i> and <i>mf</i>_<i>r</i> ± <i>nf</i>_<i>c</i>.</p>