Considering　the　inherent　safety　and　high　flexibility,　soft　robot　is　drawing　extensive　attention　from　both　industry　and　academics.　Soft　robots　made　of　organic　materials　show　the　merits　of　considerably　low　cost　and　ease　of　fabrication.　But,　the　precise　control　of　soft　robot　is　still　of　great　challenge.　A　sophisticated　understanding　of　the　motion　mechanics　of　organic　soft　robot　is　essential　for　accurate　control　of　this　type　of　robot.　In　this　paper,　PDMS/PEDOT:PSS　system,　which　is　developed　for　soft　robot,　is　modelled　and　simulated　using　finite　element　method.　Through　parameters　tuning,　the　dependences　of　PDMS/PEDOT:PSS　system　deformation　on　layer　thicknesses　and　electrical　current　are　acquired　and　compared　with　the　experimental　results　available　in　reference.　Furthermore,　we　proposed　a　three　layer　structure　for　soft　robot,　and　investigated　the　relationship　between　deformation　of　this　structure　and　layer　thicknesses.　Our　work　proposed　an　approach　for　precise　control　for　soft　robot　through　a　combination　of　finite　element　simulation　and　experiment　data.　Additionally,　the　three　layer　structure　we　proposed　is　demonstrated　to　be　a　promising　solution　for　high　response　speed　soft　robot.　©　Springer　International　Publishing　AG　2017.