Abstract: Cuttlefish can swim with great maneuverability by undulating their fins and can swim with high speed by jetting. To mimic the muscle structure of the cuttlefish, a kind of flexible fin unit which can bend to both sides and a kind of biomimetic mantle which can flexibly contract and expand, are developed with the structure that SMA (shape memory alloy) wires are embedded into the flexible silicone rubber. Then a kind of biomimetic undulating fin and a kind of biomimetic jet propeller based on the former design are developed to mimic the swimming mechanism of cuttlefish. And the thrust performance of both of the propellers is tested. At last, a prototype of biomimetic cuttlefish robot is developed and the swimming experiments are carried out.