For　high-power　modules　with　wire　bonding　as　the　interconnection　method,　fatigue　damage　and　cracking　at　the　bond　interface　are　important　forms　of　module　failure.　However,　the　currently　used　numerical　models　of　the　bond　interface　neglect　the　influence　of　microdefects　and　damage　evolution　of　the　interface　material　and　cannot　accurately　describe　the　degradation　process　of　the　mechanical　properties　of　the　bond　interface.　In　this　work,　the　shear　strength　of　the　Al-bonded　wire-Al　metallization　layer　bond　interface　of　an　insulated-gate　bipolar　transistor　(IGBT)　module　after　different　numbers　of　power　cycles　was　measured　via　shear　tests,　and　force-displacement　(F-　$\delta　$　)　curves　and　fracture　surface　morphologies　were　obtained.　The　experimental　results　indicate　that　the　bond　interface　strength　decreases　significantly　as　the　number　of　power　cycles　increases.　To　describe　this　phenomenon,　the　cohesive　zone　model-based　finite　discrete　element　method　(CZM-based　FDEM)　is　introduced　in　the　bonding　zone;　that　is,　the　bonding　zone　is　discretized　via　triangular　elements,　and　cohesive　elements　are　inserted　between　adjacent　triangular　elements　to　describe　the　cracking　process　of　the　bond　interface.　By　randomly　assigning　different　material　property　parameters　to　the　cohesive　elements,　the　microdefects　can　be　characterized,　and　by　adjusting　the　proportions　of　cohesive　elements　with　different　strengths,　the　phenomenon　whereby　the　bond　interface　strength　decreases　during　power　cycling　can　be　better　demonstrated.　Finally,　a　comparison　with　the　results　of　shear　tests　validated　that　this　method　can　effectively　predict　fracture　processes　at　the　bond　interface　and　is　able　to　describe　the　degradation　of　the　interfacial　mechanical　properties　observed　in　the　experiments.