Abstract: With the commercial development of high temperature gas-cooled reactor (HTGR), higher requirements for large-scale production of overcoated particles of fuel elements were put forward. The impacts of rotating speed of drum on dynamic surface angle, repose angle and particle size distribution were studied. The key process parameters were optimized and determined, and the causes of unqualified particles were also analyzed. The results of batch experiments using optimized parameters show that the yield is high and stable and the average yield reaches 93-94%. The overcoating equipment is easy to operate and control, and can satisfy the scale production.