In order to explore and improve the milling force of vermicular graphite cast iron RuT500,TiAlN/AlCrN and TiCN/Al2O3 composite coated carbide tools were selected to mill RuT500 based on single factor test,the influence of coating and milling parameters on the workpiece milling force was explored,and an empirical milling force model was established.The results show that compared with TiAlN/AlCrN carbide tool,TiCN/Al2O3 carbide tool can produce more milling force when milling RuT500;the most significant factor influencing the milling force of vermicular cast iron is the amount of back cutting tool,followed by the amount of feed,and the milling speed has relatively little influence on the milling force;when TiAlN/AlCrN carbide tool is used,the milling parameters interactions have significant influence on milling force of vermicular graphite cast iron.Small milling force and higher working efficiency can be gained with larger amount of back cutting tool,proper amount of feed and larger milling speed.