In　order　to　study　the　evolution　rule　of　heterogeneous　traffic　flow　under　the　background　of　IOV　(internet　of　vehicles),　the　concept　of　relative　entropy　in　introduced　to　quantitatively　describe　the　orderliness　of　heterogeneous　flow,　and　analyze　the　inner　link　among　orderliness,　market　penetration　rate　of　CAV　(connected　and　autonomous　vehicle)and　the　number　of　queues　for　CACC　(cooperative　adaptive　cruise　control).　Then,　it　is　deduced　that　the　increase　on　the　market　penetration　rate　of　CAV　and　decrease　on　the　number　of　queues　can　improve　the　orderliness　of　heterogeneous　flow.　Second,　two　improved　lane　change　strategies　for　CAVs　are　proposed,　namely,　conservative　aggregation　(CSA)　and　radical　aggregation　(RDA).　Through　the　simulation　test　of　cellular　automata,　the　advantages　and　disadvantages　of　no　aggregation　(NOA),　conventional　aggregation　(CVA),　CSA,　and　RDA　are　compared　in　terms　of　traffic　capacity,　relative　entropy　and　average　queue　length.　Finally,　the　effect　of　different　limits　of　minimum　queue　size　on　traffic　capacity　is　analyzed　with　the　lane　change　strategy　of　CSA.　The　results　show　that　the　use　of　lane　change　strategy　can　prompt　the　CACC　collaborative　queue　in　CAV　and　orderly　heterogeneous　flow.　It　improves　traffic　capacity　in　the　density　range　from　20　to　95　veh/km.　Compared　with　the　NOA　strategy,　the　CSA　strategy　increases　the　traffic　capacity　by　12.6%,　and　the　RDA　strategy　by　14.0%.　However,　when　the　market　penetration　rate　of　CAV　is　0.8,　the　maximum　traffic　capacity　of　the　RDA　strategy　is　reduced　by　25.8%.　According　to　the　quantitative　description　of　relative　entropy　for　the　aggregation　degree　of　CAV　in　heterogeneous　flow,　four　lane　change　strategies　(NOA,　CVA,　CSA　and　RDA)　increases　the　aggregation　degree　of　CAV　in　turn.　In　the　CSA　strategy,　when　the　minimum　queue　size　of　CACC　takes　4　vehicles,　the　efficiency　of　traffic　capacity　is　the　optimal.　©　2023　Science　Press.　All　rights　reserved.