Abstract: Solid particles have emerged as a promising new heat transfer and storage medium for solar thermal power generation, offering the potential to improve efficiency. Using bauxite inert particles as the research object, a three-chamber attrition test rig was used to obtain the particle attrition resistance and particle size distribution variation rules. The particles experienced a mass loss of approximately 2.5% after 120 hours, and the most effective simulation was achieved when the mass exchange ratio in the particle size distribution evolution model was in accordance with a normal distribution （σ = 1/2,d_s= 4d）. To extend these findings to the solar thermal power system, an attrition conversion coefficient was proposed using attrition dissipation energy as an intermediate quantity.Using a 100 kWe system as an example, it’s calculated that one cycle of bauxite inert particles between the system devices is equivalent to 0.0114 hours of operation in a three-chamber attrition test rig. These findings offer valuable insights for the calculation of long-term system economics and the development of operating strategies.