This　article　studies　the　control　barrier　function (CBF)　guided　tracking　performance　optimization　for　switched　systems　under　iterative　learning　control　(ILC).　CBF　is　an　effective　method　for　handling　control　system　state　safety.　If　the　safe　set　is　designed　as　expected　performance,　and　the　unsafe　set　is　not　expected,　then　this　may　be　a　good　choice　for　optimizing　control　system　performance.　We　propose　a　tracking　performance　optimization　method　based　on　CBF　to　speed　up　the　convergence　of　the　tracking　error.　A　safe　set　is　used　to　describe　the　expected　tracking　performance,　by　utilizing　CBF,　safety　is　further　transformed　into　a　set　of　inequality　conditions　that　constrain　ILC　controller　gains,　which　ensures　that　the　tracking　error　is　always　within　the　safe　set.　In　addition,　an　event‐triggering　mechanism (ETM)　is　considered　to　reduce　unnecessary　data　transmission,　and　sufficient　conditions　for　exponential　stability　of　the　tracking　error　of　switched　systems　and　ILC　controllers　design　are　obtained.　Finally,　a simulation　example　is　given　to　verify　the　feasibility　of　the　proposed　method.