In　the　simulation　of　metal　forming　process,　each　node　is　given　several　codes　to　represent　its　velocity　constraint.　If　coded　properly,　these　codes　can　be　used　to　generate　a　position　code　for　the　boundary　node,　afterwards,　position　codes　of　two　endpoints　of　a　boundary　edge　can　be　employed　to　describe　the　location　of　this　boundary　edge,　and　the　possible　type　of　heat　transfer　on　it　as　well.　This　method　makes　the　dynamic　treatment　for　the　temperature　boundary　condition　easy　and　reliable.