The　battery　energy　storage　technology　can　be　flexibly　configured　and　has　excellent　comprehensive　characteristics.　In　addition　to　considering　the　reliability　of　the　battery　energy　storage　power　station　when　it　is　connected　to　the　grid,　the　reliability　of　the　energy　storage　power　station　itself　should　also　be　considered.　The　reliability　model　based　on　Copula　theory　was　established　for　battery　module,　and　the　reliability　of　energy　storage　module　was　analyzed　according　to　the　basic　structure　of　energy　storage　modules.　In　this　paper,　the　example　analysis　is　based　on　the　existing　simulation　model　of　energy　storage　module.　Then　the　reliability　of　energy　storage　module　in　the　next　20　years　is　predicted　considering　the　different　correlations　between　battery　clusters.　©　2022　IEEE.