The　sound　characteristic　is　a　critical　metric　to　manifest　the　brand　differentiation　of　electric　vehicle　(EV),　and　the　sound　design　with　more　diverse　acoustic　characteristics　has　become　a　hot　issue　in　current　research　of　EV　technology.　In　this　paper,　an　efficient　technique　of　active　sound　design　(ASD)　is　explored　to　develop　the　control　system　of　active　sound　generation　(ASG)　with　powerful　sound　quality　for　EV.　Firstly,　an　optimization　algorithm　of　sound　synthesis　based　on　multi-frequency　superimposition　is　proposed　to　improve　the　harmonic　interference　phenomenon　in　the　synthesized　sounds.　Subsequently,　an　adaptive　sound　control　strategy　is　formulated,　where　an　iterative　accumulation　method　is　proposed　to　calculate　the　＂virtual　engine　speed＂　of　EV,　and　a　gain　table　is　presented　to　divide　the　running　state.　Besides,　an　ASG　system　is　developed　based　on　the　proposed　ASD　technique.　The　tests　result　demonstrate　that　there　are　18　target　order　sounds　are　reproduced　perfectly,　and　the　powerful　sound　quality　interior　EV　is　enhanced　while　the　original　interior　acoustic　environment　of　EV　is　retained,　which　confirms　the　effectiveness　of　the　proposed　control　technique　of　ASG　system.　The　proposed　ASD　technique　here　accelerates　the　change　from　silence　to　sound　quality　in　the　electric　vehicles,　which　has　important　theoretical　significance　and　engineering　value.