Taking　InGaAs/GaAs　strained　quantum　wells　as　an　example,　the　6　×　6　Luttinger-Kohn　Hamiltonian　considering　the　valence　band　mixing　and　the　wave　function　mixing,　and　by　using　the　finite-difference　method　to　solve　the　Luttinger-Kohn　Hamiltonian　of　the　effective　mass　equation　are　introduced.　Then　the　conduction-band　structures　and　the　valence-band　structures　are　obtained.　The　transition　matrix　element　of　strained　quantum　well,　and　the　material　gain　with　linear　Lorentzian　function　are　also　calcuated.　Finally　the　well　width,　carrier　concentration,　temperature　and　other　factors　which　influence　the　gain　material　are　discussed.　The　results　show　that　the　compressive　strain　makes　the　effective　quantum　well　bandgap　increase,　reduces　the　transparency　of　the　material　gain　current　density,　and　then　lower　the　threshold　of　the　device　to　improve　the　output　characteristics　of　the　device.　The　right　deviation　between　the　gain　peak　wavelength　and　the　emission　wavelength　make　optically　pumped　semiconductor　laser＇s　threshold　current　and　operating　current　have　small　changes　in　temperature.