Servo　system　is　a　kind　of　automatic　control　system　which　occupies　a　position　of　importance.　In　the　light　of　complication　in　the　design　of　servo　system,　this　paper　introduces　an　intellectualize　CAD　system　(SSCAD)　and　presents　a　new　method　of　intelligent　design.　This　method　is　on　the　basis　of　SSCAD　and　uses　a　dynamic　design　method　which　is　a　combination　of　typical　example　analogy,　traditional　design　correction　and　experiment　verification.　The　theoretical　bases　of　this　method　are　also　given　in　this　paper.　The　design　example　shows　that　this　method　is　simple,　easy　and　efficient,　therefore,　has　a　higher　practical　value.