The　ultrafast　thermalization　processes　of　Au　film　irradiated　by　multi-pulse　sequences　with　variable　temporal　separation　were　investigated　by　numerical　simulations.　Two　temporally　sequential　thermal　relaxation　mechanisms　including　the　two　temperature　relaxation　and　the　thermal　diffusion　relaxation　were　demonstrated.　With　inclusion　of　the　electron　ballistic　effect,　we　obtained　the　full　2-D　temperature　fields　evolution　dominated　by　the　two　distinct　relaxation　mechanisms.　It　is　proposed　that　the　laser　thermalization　processes　can　be　greatly　promoted　through　choosing　the　optimized　temporal　separation　of　the　pulse　train.　We　also　found　that　the　two　temperature　relaxation　period　can　be　modulated　by　changing　the　pulse　train　parameters　such　as　the　temporal　separation,　the　pulse　durations　and　the　pulse　number　in　a　train.　(C)　2010　Elsevier　B.V.　All　rights　reserved.