The invention discloses a nanoscale particle simulation substrate reprocessing method, which comprises the following steps of: providing a particle simulation substrate, wherein the particle simulation substrate comprises a substrate and a thermal oxide layer positioned on the surface of the substrate, and the thermal oxide layer has a test surface; and chemically mechanically polishing the thermal oxide layer along the test surface, so that the number of particles on the polished test surface is less than 100. By the substrate reprocessing method provided by the invention, production cost is saved.