Ion　doping　has　been　demonstrated　as　a　practical　approach　to　achieving　highly　efficient　luminescence　in　both　inorganic　phosphors　and　organic-inorganic　hybrids.　The　asformed　doping　species　show　great　potential　in　optoelectronic　applications　due　to　their　high　photoluminescence　quantum　yield　(PLQY)　and　excellent　stability.　Herein,　we　report　highly　emissive　Sb3+-doped　indium　halides　(C6H18N2)InCl5　center　dot　H2O:Sb(C6H8N22+　=　N,N,N＇,N＇-tetramethylethane-1,2-diammonium)　prepared　by　solution　evaporation　methods　with　an　emission　that　peaked　at　565　nm　and　a　PLQY　of　74.6%.　Photophysical　characterizations　and　density　functional　theory　computational　studies　verify　the　broadband　emission　originating　from　a　self-trapped　exciton.　Interestingly,　a　drastic　red　shift　of　the　emission　peak　from　565　to　663　nm　with　yellow　luminescence　turning　to　red　is　observed　once　the　(C6H18N2)InCl5　center　dot　H2O:Sb　hybrid　is　exposed　to　methanol　vapor.　Moreover,　when　the　methanol-exposed　hybrid　is　put　in　air,　the　emission　reverts　to　565　nm　in　several　minutes.　Single-crystal　X-ray　diffraction　studies　show　a　subsequent　structure　distortion　upon　the　coordination　of　methanol　to　the　Sb(III)　center,　which　is　responsible　for　the　drastic　red　shift　of　the　emission.　Encouragingly,　we　found　that　(C6H18N2)InCl5　center　dot　H2O:Sb　exhibits　a　specific　response　to　methanol　vapor　after　screening　a　series　of　volatile　organic　compounds　with　different　polarities.　Besides,　a　negligible　change　of　the　emission　intensity　is　observed　after　several　cycles　of　uptaking　and　releasing　methanol.　The　high　fatigue　resistance　and　specific　solvent　response　of　the　Sb3+-doped　indium　halide　make　it　a　very　promising　methanol　detector.