Large-scale　activities　usually　put　heavy　pressure　on　urban　transportation　systems.　The　research　constructs　an　evaluation　index　system　from　three　dimensions:　time,　space,　and　degree　of　impact　on　traffic　operation　in　the　surrounding　areas　of　venues.　The　index　values　are　calculated　based　on　bus　IC　card　data,　subway　AFC　data,　urban　road　detector　data,　taxi　meter　data,　and　GPS　data.　Maximizing　deviation　is　used　to　assign　a　weight　to　the　evaluation　index　and　the　traffic　impact　index　of　urban　large-scale　activities　is　obtained　by　weighting　calculation.　Finally,　the　research　uses　the　K-means　clustering　method　to　grade　the　traffic　impact　degree　of　urban　large-scale　activities.　The　research　takes　the　large-scale　activities　held　in　Beijing　workers＇　stadium　in　recent　years　as　an　example　to　verify.　Results　show　that　the　method　proposed　in　the　article　has　good　applicability　and　can　clearly　distinguish　the　impact　degree　of　large-scale　activities　on　traffic　operation.　©　ASCE.