Study　on　the　silicon-based　nanomechanical　electro-thermal　probe　array　used　for　high　density　storage　has　been　performed.　After　introduction　of　the　structure　and　working　principle　of　the　NEMS　probe,　design　of　component　analysed　with　theoretical　calculation　and　Finite　Element　Method　(FEM).　Using　the　(micro-)nano-machining　technology,　the　piezoresistor　and　the　heater　were　integrated　on　the　silicon　microcantilever　and　the　component　was　fabricated.　Subsequently,　the　electro-thermal　performance　and　sensitivity　were　tested　and　the　results　agree　well　with　their　simulation.　About　31.6Gb/in2　a　real　data-writing　density　was　realized　successfully　on　PMMA　polymer　thin　film　by　using　AFM　equipment　with　the　optimized　thermal　writing　parameters.