Higher　cutting　speed　is　always　the　pursuit　of　industries　as　it　is　one　of　the　most　effective　methods　to　improve　machining　efficiency,　which　requires　a　better　understanding　of　deformation　and　microstructure　evolution　process　during　chip　formation.　In　this　study,　chip　formation　process　is　divided　into　three　different　sections　of　preloading,　loading　and　unloading　to　analyze　the　mechanisms　of　microstructure　evolution　sequentially　through　a　coupled　finite　element　and　cellular　automata　approach.　The　non-uniform　distributed　fields　of　strains,　strain　rates　and　temperatures　induced　by　different　stage　during　chip　formation　process　are　obtained　and　then　transferred　as　boundary　conditions　for　microstructure　evolution.　In　pre-loading　condition,　microstructure　evolution　appears　only　along　shear　band　with　small　sizes,　which　provides　more　boundaries　for　activation　of　DRX　mechanisms　in　following　conditions.　Final　microstructures　always　show　a　gradient　distribution　along　shear　direction,　and　secondary　shear　zone　makes　the　greatest　contribution　to　grain　refinement.　Average　grain　sizes　and　microstructure　distribution　have　shown　a　good　agreement　between　experimental　data　and　simulation　results,　which　indicates　that　this　sequential　simulation　approach　can　perform　a　better　description　of　those　process　characteristics　of　microstructure　evolution　during　a　continuous　process　with　complicated　boundary　conditions.