The　diversification　of　locomotion　modes　can　expand　the　movement　range　of　mobile　robots,　and　enhance　their　adaptability　to　complex　environments.　While　the　combination　of　two　locomotion　modes　is　quite　common,　there　is　still　considerable　scope　for　enhancing　the　environmental　adaptability　of　such　robots.　In　this　article,　an　armadillo-inspired　robot　(AIRO)　with　two　motion　modes,　crawling,　and　rolling,　is　designed　and　developed.　According　to　the　proposed　mechanism　design　method　based　on　layered　constraints,　a　one-degree　of　freedom　six-bar　trunk　mechanism　is　designed　and　evaluated　according　to　the　kinematic　chain　and　the　actual　configurations,　which　can　realize　the　switching　between　crawling　and　rolling　modes　with　only　one　motor,　and　has　the　advantages　of　simple　control　and　high　structural　stiffness,　and　then　the　C-shaped　arc　legs　are　designed　to　satisfy　the　kinematic　requirements.　Finally,　a　single/multiple　motion　modes　performance　score　formula　is　proposed　to　quantitatively　evaluate　the　robot＇s　mobility　performance　based　on　the　indexes　such　as　stability,　energy　consumption,　and　speed.　The　developed　prototype　of　AIRO　weighs　2.35　kg　and　has　a　maximum　size　of　469.6　mm　x　246.6　mm　x　143.2　mm.　Experimental　results　demonstrate　that　AIRO　achieves　a　maximum　crawling　speed　of　0.192　m/s　and　a　maximum　rolling　speed　of　0.464　m/s　on　flat　terrain,　which　provides　good　adaptability　to　complex　terrain.　The　research　results　provide　a　reference　for　the　development　of　similar　robots　with　multiple　motion　modes.