It　is　of　great　significance　for　disaster　prevention　and　mitigation　to　carry　out　disaster　simulations　for　dam　failure　accidents　in　advance,　but　at　present,　there　are　few　professional　systems　for　disaster　simulations　of　tailings　dams.　In　this　paper,　we　focused　on　the　construction　of　a　virtual　geographic　environment　(VGE)　system　that　provides　an　effective　tool　for　visualizing　the　dam-break　process　of　a　tailings　pond.　The　dam-break　numerical　model　of　the　tailings　dam　based　on　computational　fluid　dynamics　(CFD)　was　integrated　into　the　VGE　system.　The　infrastructure　of　the　VGE　was　supported　by　a　3-D　geographic　information　system　(GIS)　with　a　user-friendly　interface　for　the　initiation,　visualization,　and　analysis　of　the　dynamic　process　of　tailings　dam　failure.　Key　technologies,　including　the　integration　of　numerical　models,　rendering　of　large-scale　scenes,　and　optimizations　of　disaster　simulation　and　visualization,　were　discussed　in　detail.　In　the　prototype　system,　information　on　the　run-out　path,　travel　distance,　etc.　can　be　obtained　to　visually　describe　the　flow　motion　released　by　two　dam　failure　cases.　The　simulation　results　showed　that　the　VGE　can　be　used　for　the　multidimensional,　dynamic　and　interactive　visualization　of　dam-break　disasters,　and　can　also　be　useful　for　assessing　the　risk　associated　with　tailings　dams.　©　2021　Informa　UK　Limited,　trading　as　Taylor　&　Francis　Group.　The　International　Journal　of　Digital　Earth　is　an　Official　Journal　of　the　International　Society　for　Digital　Earth.