Abstract: For the problem of multi-dimensional vibration damping for driver’s seat, Stewart double triangle mechanism was used as main structure of seat’s suspension, parameter optimization design was then executed accord to the vehicle's natural frequencies and sensitive frequency range of the human body. Researches show that the natural frequencies of Stewart double triangle parallel suspension not only avoid the vehicle's natural frequencies, but also away from the sensitive frequency range of the human body in vertical, pitch and roll direction after optimization design.