The　influence　of　curvature　variation　on　the　crystallinity　and　luminescence　of　GaN-based　blue　laser　diode　(LD)　structure　is　comprehensively　investigated　during　the　growth　of　InGaN/GaN　active　layers.　Compared　with　InGaN/GaN　multiple　quantum　well　(MQWs)　grown　by　the　conventional　2-temperature　deposition,　curvature　variation　is　successfully　suppressed　and　a　much　gentler　deformation　from　wells　to　barriers　is　obtained　by　employing　same-temperature　deposition　method　(STDM).　With　less　curvature　fluctuation,　the　V-pit　density　of　InGaN/GaN　MQWs　grown　on　sapphire　is　effectively　decreased　from　4.5x10(8)/cm(2)　to　2.8x10(8)/cm(2)　with　average　root-mean-square　roughness　of　0.55nm,　while　threading　dislocation　density　of　the　GaN-based　LD　structures　grown　on　FS-GaN　is　also　reduced　from　5.9x10(6)/cm(2)　to　1.6x10(6)/cm(2).　Additionally,　an　7nm　redshift　in　photoluminescence　emission　for　LD　structure　is　achieved,　accompanied　by　a　6　times　higher　emission　intensity.　A　more　uniform　distribution　of　emission　wavelength　along　the　radial　direction　is　observed　and　the　full　width　at　half　maximum　is　also　narrowed,　indicating　that　the　STDM　is　advantageous　to　effectively　eliminate　the　negative　influence　of　curvature　variation　and　contribute　to　fabricating　high-performance　GaN-based　light-emitting　diodes　and　LDs.