Flexible　composites　as　sensors　are　applied　under　a　small　voltage,　but　the　effect　of　the　external　electrical　field　on　the　resistance　is　always　ignored　and　unexplored　by　current　research.　Herein,　we　investigate　the　electrical　resistance　relaxation　of　anisotropic　composites　when　they　are　subjected　to　an　external　electric　field.　The　anisotropic　composites　were　3D-printed　based　on　carbon-fiber-filled　silicon　rubber.　Constant　DC　voltages　were　applied　to　the　composites,　and　the　output　electrical　current　increased　with　time,　namely　the　electrical　resistance　relax　with　time.　The　deflection　and　migration　of　carbon　fibers　are　dominantly　responsible　for　the　resistance　relaxation,　and　the　angle＇s　evolution　of　a　carbon　fiber,　under　the　application　and　removal　of　the　electrical　field,　was　well　observed.　The　other　factor　hindering　the　resistance　relaxation　is　the　increased　temperature　originating　from　the　Joule　heating　effect.　This　work　provides　a　new　understanding　in　the　working　duration　and　the　static　characteristics　of　flexible　composites.