A　comprehensive　assessment　of　the　consequences　of　dam-break　is　a　critical　strategic　necessity　for　guaranteeing　socio-economic　development　and　lives　for　individuals.　The　consequences　of　dam-break　are　affected　comprehensively　by　a　multitude　of　uncertainties,　resulting　in　multi-source　and　inconsistent　relationships　between　indicators.　It　is　extremely　tough　to　integrate　information　from　different　sources　adequately　under　multiple　uncertainties,　which　often　limit　the　assessment　reliability.　In　this　work,　a　comprehensive　uncertainty　evaluation　methodology　for　the　consequences　of　dam-break　was　developed　through　multi-source　information　fusion.　Firstly,　cloud　model　was　employed　to　deal　with　randomness　and　fuzziness　in　the　quantification　of　the　grading　of　indicators　and　constructed　the　basic　probability　assignment　function　of　the　evidence　corresponding　to　each　data　source.　Then,　in　order　to　address　the　issue　that　conflicting　evidence　cannot　be　effectively　fused　utilizing　traditional　evidence　theory.　The　basic　probability　assignment　function　was　fused　by　the　improved　evidence　theory.　Furthermore,　due　to　the　differences　in　the　importance　of　each　data　source　in　the　assessment　process.　The　corresponding　weights　were　determined　employing　trapezoidal　fuzzy　analytic　hierarchy　process　and　entropy　weight　method.　Finally,　the　effectiveness　of　the　method　was　verified　by　taking　five　reservoirs　in　the　Haihe　River　Basin.　It　shows　that　multiple　uncertainties　from　different　sources　of　information　are　combined　and　handled　and　the　severity　grades　of　consequences　of　dam-break　can　be　quantitatively　analyzed　with　our　assessment　method.　Meanwhile,　multi-source　information　with　conflicts　and　uncertainties　can　be　approached　to　produce　more　reliable　risk　assessment　results　in　the　situation　of　highly　conflicting　evidence.　©　The　Author(s),　under　exclusive　licence　to　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2024.