<p>To clarify the correlation mechanism between high temperature and iron element diffusion on the tribological properties of ceramic brake pad materials, an investigation was conducted in this study. Two groups of test samples of ceramic brake pad were prepared and heated to 200–600 °C in air and iron powder medium, respectively. Then, the surface morphology, hardness, chemical element, and tribological properties were all measured and obtained with a white light interferometer, an XRD instrument, and an MWF-500 friction tester, respectively. The results show that high temperature has a significant effect on the physical and mechanical properties of ceramic brake pad materials. With the increasing of heating temperature, the surface morphology and hardness of the samples show a decreasing trend that led to a poor tribological properties especially for temperatures above 300 °C. For the case in iron powder medium, worse surface morphology is observed due to the iron element diffusion, and a larger friction coefficient and wear quantity are induced. The main reason is that the ceramic brake pad is a compound material composed of SiC, SiO₂, CaCO₃, and Al₂O₃, and a chemical reaction is inevitably produced between SiO₂ and CaCO₃ at above 300 °C. When the test sample is heated in iron powder medium, FeAl₂O₄ and Fe₂SiO₄ with lower hardness were observed due to the diffusion of iron elements. Thus, a worse tribological property is obtained because of high surface roughness and low hardness. This study provides a theoretical foundation and application reference for the quality improvement of ceramic brake pad material.</p>