Purpose　-　The　purpose　of　this　paper　is　to　present　a　stretched　backboneless　continuum　manipulator,　which　aims　to　provide　sufficient　inner　room　for　potential　transportation　of　objects　or　fixture　of　necessary　devices,　and　to　reduce　the　number　of　motors　for　reduction　of　the　weight　of　the　system.　Design/methodology/approach　-A　mathematical　model　of　the　presented　manipulator　is　established　in　this　paper.　To　verify　the　presented　theory,　the　position　of　the　free　end　was　recorded　by　a　high-resolution　digital　camera　in　experiment.　According　to　the　comparison　of　experimental　values　and　theoretical　values,　the　error　is　less　than　2.5　per　cent.　It　shows　that　the　mathematical　model　and　theoretical　analysis　are　reasonable;　the　presented　continuum　manipulator　can　reach　to　desired　postures　and　positions.　Findings　-　This　paper　presents　a　new　stretched　backboneless　continuum　manipulator　supported　and　driven　by　cannula　tendons.　The　cannula　tendons　are　composed　of　rubber　tubes　and　glass　fibers.　The　upper　section　and　the　lower　section　of　the　presented　manipulator　are　driven　by　same　motors.　For　steering　the　manipulator,　switched　driving　strategy　is　developed　based　on　the　presented　kinematics　model.　The　presented　manipulator　possesses　six　degrees　of　freedom　(DOFs)　and　has　good　performance　in　dealing　with　complex　working　environment.　The　experiment　verifies　the　presented　driving　strategy.　Research　limitations/implications　-　The　presented　backboneless　continuum　manipulator　has　only　two　sections　and　is　supported　by　cannula　tendons.　Extending　this　structure　to　further　more　sections　is　a　challenge　and　is　left　for　future　research.　Originality/value　-　The　value　of　this　study　is　to　propose　a　stretched　backboneless　continuum　manipulator,　which　can　provide　inner　room　as　large　as　possible　for　potential　usage　and　halve　the　number　of　motors,　for　which　a　switched　driving　strategy　is　put　forward.　As　a　result,　the　weight　and　complexity　of　the　manipulator　are　decreased.　The　presented　manipulator　is　able　to　move　in　potential　complex　environments　and　approach　its　objects　in　different　postures　in　virtue　of　its　high　flexibility　and　its　six　DOFs.