In　order　to　solve　the　problem　of　the　decision　makers＇　psychological　behavior　in　case-based　decision,　a　case-based　decision　method　for　gas　explosion　considering　decision　maker＇s　regret　aversion　is　proposed.　Firstly,　for　the　calculation　of　case　similarity,　the　problem　attributes　are　expanded　to　six　types,　including　symbol　data,　crisp　data,　interval　data,　triangular　fuzzy　number,　multi-granularity　linguistic　variable　and　intuitionistic　fuzzy　number.　The　perceived　utility　is　then　calculated　based　on　the　consideration　of　the　decision　maker＇s　regret　aversion,　and　the　case　similarity　is　evaluated　by　weighted　summation.　Furthermore,　the　perceived　utility　of　alternative　implementations　is　calculated,　and　the　comprehensive　perceived　utility　is　gained　by　integrating　the　perceived　utility　of　case　similarity　with　the　perceived　utility　of　alternative　implementations.　On　the　basis　of　the　above,　the　optimal　alternative　is　generated　according　to　the　comprehensive　perceived　utility.　Finally,　an　illustrative　example　is　provided　which　shows　the　validity　and　feasibility　of　the　proposed　method.　©　2020,　Zhejiang　University　Press.　All　right　reserved.