Flexible　sensors　at　small　scales　have　potential　applications　in　many　fields.　Until　now,　the　research　on　high-performance　vibration　sensors　based　on　soft　materials　with　high　sensitivity　and　precision,　fast　response　and　high　stability　are　still　in　its　infancy.　In　this　work,　a　flexible,　wearable　and　high　precision　film　sensor　based　on　multi-walled　carbon　nanotube　(MWCNT)　was　prepared　via　a　vacuum　filtration　process　and　then　encapsulated　within　polydimethylsiloxane　(PDMS).　The　sensor　exhibits　an　ultrahigh　sensitivity　with　gauge　factor　of　214.3　at　flexural　strain　of　0.4%.　When　used　to　monitor　the　vibration　responses　of　a　carbon-fiber　beam　induced　by　the　base　excitation　and　impact　hammer,　the　time　and　frequency　responses　were　comparable　with　the　results　obtained　by　the　accelerometer,　with　difference　less　than　1\!%.　In　addition,　when　the　MWCNT/PDMS　thin　film　was　employed　as　an　electronic　skin　sensor　attached　on　the　human　body　to　detect　human　activities,　the　high　sensitivity　and　repeatability　demonstrate　a　great　potential　application　in　monitoring　human　motion.　©　2020　IOP　Publishing　Ltd.