Connected　and　autonomous　vehicles　(CAVs)　are　developing　rapidly　nowadays.　In　the　near　future,　we　may　see　human-driving　vehicles　(HVs)　and　CAVs　running　on　the　same　road.　The　characteristics　of　human　drivers　and　the　interaction　between　HVs　and　CAVs,　therefore,　need　to　be　further　studied.　All　these　factors　will　have　a　great　impact　on　traffic　operation.　This　paper　aims　to　explore　a　modeling　method　to　analyze　the　operation　mechanism　of　mixed　traffic　flows　of　HVs　and　CAVs.　Considering　HV　drivers＇　cognitive　behavioral　characteristics　and　HV-CAV　interaction　effects,　the　forward　and　lateral　movement　rules　of　HVs　and　CAVs　are　proposed　based　on　the　Cellular　Automata　model.　Then　the　fundamental　diagram,　congestion　degree,　lane-changing　frequency,　and　time-spatial　diagram　are　obtained　by　numerical　simulation.　The　results　show　that　the　presence　of　CAVs　is　positively　related　to　macroscopic　traffic　parameters,　including　velocity,　flow　and　critical　density.　CAVs　help　to　relieve　traffic　congestion　and　instabilities.　The　congestion　degree　of　pure　CAV　traffic　flow　is　about　1/3　that　of　pure　HV　traffic　flow.　When　the　CAV　penetration　rate　is　relatively　low,　the　interaction　between　HV　and　CAV　has　a　significant　impact　on　traffic　operation.　Specifically,　when　the　CAV　penetration　rate　is　below　0.5　similar　to　0.6,　increasing　the　CAV　penetration　rate　will　increase　the　lane-changing　frequency　of　the　whole　traffic　flow.(c)　2022　Elsevier　B.V.　All　rights　reserved.