The　localized　electric　field　enhancement　of　Au-Ag　nanorods　dimer　is　theoretically　investigated　based　on　finite　element　method　(FEM).　An　analytical　mutual-interference　model　between　asymmetric　dipole-dimer　has　been　built　to　describe　the　dipoles　coupling　with　different　resonance　modes　in　heterogeneous　dimer.　Three　prominent　enhancement　peaks　could　be　observed　from　ultraviolet　to　visible　spectrum,　in　which　the　ultraviolet　resonance　especially　corresponds　to　a　higher　mode　in　both　Ag　and　Au　nanorods.　The　results　reveal　the　strong　coupling　mechanism　among　different　dipoles　existing　in　the　asymmetric　dipole　system,　which　could　support　the　design　of　plasmonic　nanodevices　in　larger　resonance　wavelength　range.