As an effective technology in preventing metal structures inside marine environment from corrosion the cathodic protection has been widely used for shallow-water oil & gas processing facilities. On the other hand parameters like temperature pressure and dissolved oxygen content in deep-water area are quite different from those in shallow-water area bringing lots of uncertainties and difficulties for the applications of CP technology. In the present work the protection potential range service performances of anode materials as well as the anode arrangement for carbon steel and stainless steel under deep-water environment are studied. Both the protection potential ranges of carbon steel and stainless steel and the variation of protection current are obtained through indoor experiments and besides an effective anode distribution in case carbon steel is coupled to stainless steel is also analyzed using numerical simulations. The results are helpful in applying CP technologies for oil & gas pipelines under deep-water environments.