A　method　to　analyze　the　short-time　withstand　current　for　air　circuit　breaker　(ACB)　is　presented.　The　cylindrical　contact　bridge　is　adopted　to　describe　the　current　constriction　between　the　movable　and　fixed　contacts,　and　then　the　corresponding　electromagnetic　force　and　temperature　rise　of　the　contacts　are　calculated.　Finally,　the　short-time　withstand　current　capability　could　be　evaluated　based　on　the　temperature　rise　of　the　contacts.　In　addition,　the　influence　of　the　number　of　the　contacts,　the　contact　force　and　contact　size　on　the　short-time　withstand　current　capability　is　analyzed.　©　2011　IEEE.