To　investigate　primary　breakup　close　to　an　injector,　this　paper　presents　both　experimental　and　numerical　research　on　high-pressure　common-rail　diesel　injection.　We　propose　a　new　method　named　SD-ELSA　model　to　realize　automatically　identifying　droplet　features　for　high-pressure　diesel　spray　based　on　the　classic　ELSA　(Eulerian　Lagrangian　Spray　Atomization)　model;　this　method　is　suitable　for　varied　injection　operation　conditions.　The　SD-ELSA　first　identifies　the　liquid　bulk　due　to　breakup　of　the　continuous　phase　in　near　field,　and　then　converts　the　Eulerian　liquid　bulk　into　Lagrangian　particles　to　complete　the　calculation　of　the　total　spray　atomization.　The　SD-ELSA　model　adopts　two　key　criteria,　i.e.,　the　sphericity　(S)　and　the　particle　diameter　(D);　the　qualified　liquid　mass　is　transformed　into　Lagrangian　particle,　realizing　the　coupling　of　the　Eulerian-Lagrangian　model.　The　SD-ELSA　model　illustrates　the　total　diesel　spray　atomization　process　from　the　breakup　liquid　column　to　the　droplets.