by　comparing　the　structures　of　(Inter-cavity　sub-wavelength　grating)　ISWG-VCSEL,　(Top　DBR　inter-cavity　sub-wavelength　grating)　TIWG-VCSEL,　and　(Surface　sub-wavelength　grating)　SSWG-VCSEL,　we　find　the　structure　of　ISWG-VCSEL　wavelength　tuning　range　is　the　largest,　its　tuning　range　can　reach　51nm.　Then　based　on　ISWG　structure,　the　influence　of　grating　parameters　on　tunable　VCSEL　lasing　wavelength　was　studied,　and　the　results　show　that　as　the　increase　of　the　duty　cycle　and　thickness　of　sub-wavelength　grating,　the　lasing　wavelength　will　be　red　shift,　while　the　effect　of　the　grating　period　on　the　lasing　wavelength　is　very　small.　Because　of　the　large　tuning　range　of　ISWG-VCSEL,　it　can　reduce　business　costs　and　increase　the　flexibility　networks　nature　and　will　be　very　useful　in　spectrum　analysis　fields.　And　the　lasing　wavelength　can　be　easy　designed　by　changing　the　grating　parameters.