To　reconstruct　the　shape　of　elastic　materials,　according　to　the　Born　approximation　solution　of　the　scattering　of　three-dimensional　elastic　waves,　the　authors　analyze　the　Born　approximation　solution　of　the　two-dimensional　scattering　was　analyzed　and　discuss　the　scattering　of　the　square　void　in　long　rod　made　of　Al　was　discussed.　Identification　of　flaw　geometrical　character　is　given　by　two-dimensional　inverse　Born　approximation　under　the　condition　of　low　frequency,　and　simulated　identification　is　performed　for　three　square　voids　on　computer.　The　simulated　results　show　that　two-dimensional　inverse　Born　approximation　is　an　effective　way　for　identification　of　the　flaw.