The　mesoscopic　damage　characteristics　of　geopolymer　under　freezing-thawing　(F-T)　cycles　affect　its　macroscopic　physical　and　mechanical　properties,　which　further　influence　the　safety　of　geopolymer　buildings.　This　paper　presents　a　study　on　the　mesoscopic　damage　characteristics　of　hydrophobicity-modified　geopolymer　composites　(HM-GC)　based　on　the　CT　scanning　technique.　The　damage　degree　and　damage　distribution　characteristics　of　geopolymer　composites　(GC)　before　and　after　hydrophobic　modification　were　compared.　The　gradient　distri-bution　characteristics　of　damage　caused　by　F-T　cycles　in　HM-GC　were　further　analyzed.　The　results　show　that　the　volumetric　porosity　of　the　GC　is　always　larger　than　that　of　HM-GC　under　the　same　F-T　cycle　number,　indicating　the　hydrophobic　treatment　can　reduce　the　F-T　cycle　damage　rate　and　damage　degree.　The　results　also　show　that　the　damage　induced　by　F-T　cycles　in　GC　and　HM-GC　shows　obvious　spatial　gradient　characteristics.　As　the　F-T　cycle　number　increases,　the　average　gradient　coefficient　of　GC　increases　first　and　then　decreases,　while　the　average　gradient　coefficient　of　HM-GC　increases　first　and　then　stabilizes.　The　hydrophobic　treatment　can　reduce　the　gradient　characteristics　of　the　F-T　cycle　damage　and　improve　the　F-T　durability　of　geopolymer　composites.