Solar-blind　ultraviolet　photodetectors　(SBUV-PDs)　are　utilized　in　various　military　and　civilian　fields,　encompassing　missile　tracking,　high-voltage　detection,　and　fire　warning　systems.　Ga2O3　emerges　as　the　prime　candidate　for　such　PDs　owing　to　its　elevated　bandgap,　remarkable　thermal　stability,　and　facile　fabrication　process.　The　metal-semiconductor-metal　(MSM)　structure　garners　attention　for　its　swift　response　time　and　straightforward　preparation,　thus　becoming　a　focal　point　among　diverse　PD　architectures.　Nevertheless,　the　metal　surface　impedes　optical　absorption,　thereby　diminishing　the　quantum　efficiency　of　the　PD.　In　this　work,　we　introduce　a　nanograting　onto　the　Ga2O3　surface,　which　results　in　a　747-fold　increase　in　responsivity　in　the　SBUV　region　compared　to　a　normal　MSM　grating-free　structure.　Metal　gratings　can　induce　surface　plasmon　polaritons　(SPP),　thereby　augmenting　the　optical　absorption　of　the　PD　and　stimulating　hot　electrons　to　increase　photocurrent.　However,　the　broadband　response　caused　by　the　introduction　of　metal　gratings　is　a　common　problem.　By　optimizing　the　doping　concentration　of　the　Ga2O3　absorption　layer,　adjusting　the　incident　light　intensity,　and　reverse　voltage,　the　problem　of　broadband　response　has　been　solved.　The　responsivity　of　the　device　in　the　non-SBUV　region　is　suppressed　24-fold.　This　methodology　holds　promise　as　a　reliable　approach　for　fabricating　high-performance　SBUV-PDs.