To　date,　considerable　effort　has　been　devoted　to　determine　the　potential　toxicity　of　nanoparticles　to　cells　and　organisms.　However,　determining　the　mechanism　of　cytotoxicity　induced　by　different　types　of　nanoparticles　remains　challenging.　Herein,　typically　low　toxicity　nanomaterials　were　used　as　a　model　to　investigate　the　mechanism　of　cytotoxicity　induced　by　low　toxicity　nanomaterials.　We　studied　the　effect　of　nano-TiO2,　nano-Al2O3　and　nano-SiO2　deposition　films　on　the　ion　concentration　on　a　cell-free　system　simulating　the　cell　membrane.　The　results　showed　that　the　ion　concentration　of　K+,　Ca2+,　Na+,　Mg2+　and　SO42-　decreased　significantly　following　filtration　of　the　prepared　deposition　films.　More　specifically,　at　a　high　nano-TiO2　concentration　(200　mg　L-1)　and　a　long　nano-TiO2　deposition　time　(48　h),　the　concentration　of　Na+　decreased　from　2958.01　to　2775.72,　2749.86,　2757.36,　and　2719.82　mg　L-1,　respectively,　for　the　four　types　of　nano-TiO2　studied.　Likewise,　the　concentration　of　SO42-　decreased　from　38.83　to　35.00,　35.80,　35.40,　and　35.27　mg　L-1,　respectively.　The　other　two　kinds　of　typical　low　toxicity　nanomaterials　(nano-Al2O3　and　nano-SiO2)　have　a　similar　impact　on　the　ion　concentration　change　trend.　Adsorption　of　ions　on　nanoparticles　and　the　hydrated　shell　around　the　ions　strongly　hindered　the　ions　through　the　nanoparticle　films.　The　endocytosed　nanoparticles　could　be　released　from　the　cells　without　inducing　cytotoxicity.　Hindering　the　ion　exchange　and　disrupting　the　exocytosis　process　are　the　main　factors　that　induce　cytotoxicity　in　the　presence　of　excess　nano-TiO2　on　the　cell　surface.　The　current　findings　may　offer　a　universal　principle　for　understanding　the　mechanism　of　cytotoxicity　induced　by　low　toxicity　nanomaterials.