The　smile　effect　was　measured　in　the　process　of　semiconductor　laser　packaging　using　the　external　cavity　mirror　of　which　the　reflectance　was　greater　than　the　front　cavity　surface　of　the　semiconductor　to　form　external　cavity　semiconductor　laser.　In　measurement,　the　cylindrical　lens　was　inserted　in　the　external　cavity.　The　external　laser　cavity　was　only　formed　between　the　outer　mirror　and　the　single　light　emitting　point　in　the　cylindrical　lens　light　axis.　The　laser　threshold　of　the　light　emitting　point　was　reduced　to　output　laser　under　the　excitation　current　less　than　the　normal　threshold　value.　The　light　emitting　point　of　the　diode　laser　was　selected　one　by　one　by　moving　the　cylinder　lens,　so　the　smile　effect　was　measured　by　summarizing　all　beam　position.　The　low　current　is　no　harmful　effects　on　the　diode　laser　bar,　and　the　influence　of　the　other　emitters　on　CCD　is　avoided　by　measuring　single　emitter.　©　2017,　Science　Press.　All　right　reserved.