To obtain the relationship between the grinding particles size, internal structure and thermal decomposition characteristics of aluminum-silicon polyester coating under different rubbing conditions, and study the mechanism of toxic gas generation. LS-DYNA software was applied to calculate the blade elongation and elongation rate under different operating conditions of the compressor, and define the rubbing scenarios. In addition, APS was also applied to prepare the Al-Si polyester coating, and the rubbing tests were carried out by high-temperature ultra-high-speed abrasion test machine. Furthermore, SEM and EDS were used to characterize the size, morphology and composition of the grinding particles under different rubbing scenarios. Thermal decomposition tests were conducted on rubbing particles using GC-MS to obtain the thermal decomposition patterns and harmful substances that cause cabin air pollution. The results showed that the average size of the grinding particles was 30.8 μm at low feed rate (28 μm/s) and high speed (183 m/s); the average size of the rubbing particles was 74 μm at high speed (183 m/s) and high feed rate (257 μm/s); the average size of the grinding particles was 101.8 μm at low speed (52 m/s) and low feed rate (28 μm/s) and the average size of the rubbing particles was 119.4 μm at low speed (52 m/s) and high feed rate (257 μm/s). When the size of grinding particle was larger than 100 μm, a significant pyrolysis reaction occurred only near 550 ℃. When rubbing particle size of the coating was smaller than 75 μm, there were significant pyrolysis reactions near 210 ℃ and 550 ℃, and harmful substances such as benzene and toluene were produced. In conclusion, the size of the rubbing particles is positively correlated with the feed rate when the linear speed remains the same, and the size of grinding particles is negatively correlated with the feed rate when the feed rate is basically the same. The thermal stability of the rubbing particles is related to the size and internal structure of the particles. Due to the obvious thermal effect of coating at the high speed, the internal structure will be damaged, which results in the pyrolysis reaction of the rubbing particles at low temperature. Furthermore, the produced harmful substances will contaminate the cabin air induction.