T-2　toxin　is　one　of　the　naturally　dangerous　food　contaminants,　which　is　harmful　to　people　and　animals.　Because　of　its　strong　toxicity　and　wide　distribution,　it　is　vital　to　develop　a　rapid　and　effective　method　for　the　detection　of　T-2　toxin.　Herein,　an　excellent　hydrogel　surface-enhanced　Raman　scattering　(SERS)　chip　is　constructed　for　developing　a　novel　SERS　sensor　to　detect　T-2　toxin　using　a　portable　Raman　spectrometer.　The　SERS　chip　is　prepared　by　in-situ　Ca2+-mediated　assembly　of　silver　nanoparticles　(AgNPs)　in　PVA　solution,　followed　by　a　physical　crosslinking　possess.　The　assembled　AgNPs　produces　a　strong　localized　surface　plasmon　resonance　(LSPR)　at　around　532　nm,　which　enables　the　high　activity　of　SERS　chip　under　the　irradiation　of　532　nm　laser.　Additionally,　the　unique　structure　of　hydrogel　makes　the　obtained　chip　show　excellent　reliability　and　anti-interference　ability　in　detection.　As　a　result,　the　developed　SERS　sensor　shows　many　obvious　advantageous　including　free　of　complex　sample　pretreatment　(only　a　simple　extraction),　fast　response　(5　min),　low　limit　of　detection　(0.41　ppb),　wide　detection　range　(1-10000　ppb),　good　recoveries　(90.26-101.81　%)　and　relative　standard　deviations　(2.8-6.7　%).　Therefore,　this　SERS　sensor　provides　a　promising　choice　for　rapid　scanning　and　sensitive　detection　of　trace　T-2　toxin　in　complex　matrices.