When　the　acoustic　emission　source　is　located　by　the　Time　of　Arrival　(TOA)　method,　the　wave　velocity　is　required　to　be　constant　and　propagation　paths　between　the　sound　source　and　sensors　are　continuous.The　wave　velocity　of　signals　propagating　in　different　directions　in　the　plate　may　be　inconsistent　in　practical　applications.This　paper　proposes　a　Time　Difference　Mapping　(TDM)　method.This　method　use　the　prebuilt　database　method,　avoiding　consider　the　wave　velocity　in　the　plate,　the　wave　propagation　modes,　and　the　layout　of　sensors　in　experiments.This　method　simulates　acoustic　emission　sources　by　artificial,　records　the　time　when　the　signal　reaches　each　sensor,　finds　the　arrival　time　difference　of　different　sensor　paths,　and　filters　the　equal　time　difference　within　the　error　range　in　the　generated　time　difference　contour　map.The　minimum　difference　method　is　used　to　find　the　point　where　the　difference　between　the　actual　sound　source　data　and　the　training　map　data　is　the　smallest,　that　is,　the　position　of　the　sound　source.In　this　experiment,　four　acoustic　emission　sensors　were　arranged　on　the　steel　plate,　and　eight　points　were　randomly　selected　for　experimental　verification.Compared　with　the　TOA　method,　the　positioning　error　of　the　TDM　method　is　reduced　from　1.41%　to　0.38%.Therefore　acoustic　source　localization　is　more　accurate　by　using　this　proposed　method.　©　2020,　The　Editorial　Board　of　Journal　of　Basic　Science　and　Engineering.　All　right　reserved.