Abstract:Water chamber head is the important part，which is used for the steam generator of AP1000 nuclear island nuclear power plant. It is a typical nuclear power parts that is large-scale and deformed;the complex entire process of water chamber head，demanding process，serious tool breakage condition and low productivity seriously affect the development of China’s nuclear power industry. Water chamber head processing，processing characteristics of the water chamber head material SA508 III steel and the main damage form and the reason of chamber head machining tools are mainly discussed in this paper. And it makes virtual simulation for water chamber head processing. It also puts forward several projects to extend tool life and improve cutting efficiency aiming at the characteristics of water chamber head machining. What’s more，special layer cutting tool and Profiling milling cutter are designed to greatly improve the cutting efficiency of water chamber head.