The　effect　of　the　tensile　stress　on　the　magnetostriction　and　soft　magnetic　properties　of　the　TbDy-Fe　rare-earth　giant　magnetostrictive　thin　film　(RGMF),　synthesized　by　ion　beam　sputtering　deposition　(IBSD),　was　experimentally　investigated　by　measurement　of　cantilever　deflection　and　hysteresis　loop　with　LK-G150　laser　micro-displacement　sensor　and　alternating　gradient　magnetometer;　mathematically　modeled,　theoretically　analyzed　and　numerically　simulated　with　software　OOMMF.　The　simulated　results　show　that　the　tensile　stress　significantly　improves　the　magnetstrictive　sensitivity　of　the　TbDy-Fe　RGMF　at　a　low　magnetic　field,　but　slightly　reduces　the　saturated　magnetostrictive　sensitivity.　To　be　specific,　as　the　tensile　stress　increases,　the　coercive　force　of　the　TbDy-Fe　RGMF　decreases,　accompanied　by　an　improvement　of　the　magnetostrictive　sensitivity　at　a　low　magnetic　field.　The　simulated　and　measured　results　were　found　to　be　in　fairly　good　agreement.　©　2016,　Science　Press.　All　right　reserved.