Because　of　the　massive　work　and　high　cost　of　milling　experiments,　finite　element　analysis　technology　(FEA)　was　used　to　analyze　the　milling　process　of　ADC12　aluminum　alloy.　An　improved　Johnson–Cook　(J–C)　constitutive　equation　was　fitted　by　a　series　of　dynamic　impact　tests　in　different　strain　rates　and　temperatures.　It　found　that　the　flow　stress　gradually　increases　as　the　strain　rate　rises,　but　it　decreases　as　the　test　temperature　rises.　Compared　with　the　J–C　constitutive　model,　the　predicted　flow　stress　by　the　improved　J–C　constitutive　model　was　closer　to　the　experimental　results　when　the　strain　rate　was　larger　than　8000　s−1　and　the　temperature　was　higher　than　300　°C.　A　two-dimensional　cycloidal　cutting　simulation　model　was　constructed　based　on　the　two　J–C　constitutive　equations　which　was　validated　by　milling　experiments　at　different　cutting　speeds.　The　simulation　results　based　on　the　improved　J–C　constitutive　equation　were　closer　to　the　experimental　results　and　showed　the　cutting　force　first　increased　and　then　decreased,　with　cutting　speed　increasing,　reaching　a　maximum　at　600　m/min.　©　2020　by　the　authors.　Licensee　MDPI,　Basel,　Switzerland.