The engineering plastic polyamide 6 (PA6) was effectively pulverized to ultra-fine powder through a self-made pan-type milling equipment. A laser Diffraction Particle Size Analyzer and TEM were used to examine the particle size and the distribution of PA6 powder. The results show that the average particle size of PA6 was reduced to micrometer scale only after 15 milling-cycles and reached 50-80 nm after 30 milling-cycles. Pan milling decreased crystallinity of PA6 but did not affect its crystal type. Molecular weight and mechanical properties of PA6 dropped slightly during pan milling. The average particle size of PA6 powder could be controlled by adjusting processing conditions including milling time, temperature and the rotating speed of the milling pan.