An　improved　time　difference　mapping　method　is　proposed　to　locate　the　acoustic　emission　(AE)　source　of　composite　plate　in　order　to　solve　the　problems　of　fiber　fracture,　the　matrix　crack　defects　within　composite　plate　and　the　acoustic　velocity　in　different　propagation　direction　is　inconsistent　and　difference.　This　method　use　the　prebuilt　database　method,　avoiding　consider　the　propagation　speed　of　waves　in　the　plate　are　not　consistent　and　the　wave　propagation　modes,　and　layout　of　the　sensor　in　experiments　is　not　strictly　required.　Firstly,　in　order　to　quickly　and　accurately　select　and　delete　the　pseudo　AE　events　from　a　large　number　of　AE　data,　the　clustering　algorithm　is　used　to　automatically　identify　and　select　the　highly　correlated　AE　events　on　each　grid　node　and　construct　a　time　difference　training　database.　Secondly,　interpolation　compensation　algorithm　is　adopted　to　increase　grid　density　and　improve　grid　resolution.　Finally,　the　location　of　the　source　is　verified　by　using　the　weighted　difference　algorithm　to　verify　the　location　of　the　actual　source　in　the　test　area.　Theoretical　analysis　and　experimental　results　show　that　the　average　actual　errors　of　the　location　of　the　sound　source　is　reduced　from　26.5　mm　(using　the　traditional　time　difference　mapping　method)　to　18.0　mm　(using　the　improved　time　difference　mapping　method),　the　corresponding　average　relative　error　is　reduced　from　5.3%　to　3.6%,　and　the　overall　running　time　is　reduced　from　5　h　to　16.87　s.　The　research　shows　that　the　improved　time　difference　mapping　method　can　effectively　improve　the　location　results　and　precision　of　the　sound　source.　©　2020　Acta　Acustica.