The　traditional　contactor’s　optimization　design　process　requires　static　calculation,　prototype　production,　and　repeated　testing,　which　consumes　much　time　and　is　high　cost,　demanding　substantial　human　and　material　resources.　The　finite　element　dynamic　simulation　method　has　become　the　main　way　to　optimize　the　contactor　design　but　it　is　hindered　by　prolonged　calculation　time.　The　optimization　design　method　is　mainly　based　on　the　orthogonal　experimental　method,　which　can　only　generate　the　local　optimal　solutions　at　the　experimental　level.　Intelligent　optimization　design　algorithms　can　achieve　global　optimal　solutions　but　require　a　lot　of　iterative　calculations.　Therefore,　this　paper　proposes　an　improved　optimization　algorithm　for　the　dynamic　process　of　contactors　to　reduce　the　electromagnetic　and　mechanical　inertia　of　contactors　and　increase　the　magnetic　density.　The　response　speed　of　the　mechanism　and　the　utilization　rate　of　magnetic　materials　are　improved,　reducing　contact　bounces.　Firstly,　considering　the　external　leakage　flux　and　magnetic　field’s　distribution　characteristics　in　contactors,　an　improved　magnetic　circuit　model　is　constructed　based　on　the　three-dimensional　finite　element　dynamic　simulation　to　calculate　parameters.　Then,　an　improved　NSGA-Ⅱ　algorithm　is　introduced　for　optimization　design.　The　number　of　Pareto　fronts　is　used　to　judge　the　evolution　process　of　the　population,　and　the　adaptive　genetic　differential　hybrid　evolution　strategy　is　realized,　improving　global　convergence　and　convergence　speed.　Finally,　combined　with　a　constant　flux　closed-loop　control　strategy　and　multi-objective　optimization　design,　the　speed　response　and　magnetic　material　utilization　are　improved　by　reducing　electromagnetic　and　mechanical　inertia　while　increasing　magnetic　density　to　mitigate　contact　bounces.　Simulations　and　experiments　are　conducted　on　the　improved　magnetic　circuit　model.　The　results　show　that　the　simulation　and　experimental　waveforms　are　almost　consistent,　with　errors　of　less　than　3%　within　the　allowable　range.　Combined　with　the　improved　magnetic　circuit　model　and　the　improved　NSGA-Ⅱ　algorithm,　the　contactor　design　is　optimized　by　the　flux　linkage　closed-loop.　The　optimization　results　show　that　the　prototype＇s　holding　power　is　reduced　to　0.72　W,　the　average　bounce　time　is　reduced　to　0.7　ms,　the　average　number　of　bounce　times　is　reduced　to　2,　the　number　of　coil　turns　is　reduced　to　1　304,　and　the　magnetic　density　is　increased　from　0.54　T　to　0.73　T,　improving　the　utilization　rate　of　magnetic　materials　and　reducing　the　power　consumption.　The　following　conclusions　can　be　obtained:　(1)　An　improved　magnetic　circuit　model,　considering　the　external　magnetic　leakage　and　magnetic　field　distributions　in　the　dynamic　process　of　the　contactors,　maintains　computational　efficiency　and　accuracy　across　structural　parameters　and　control　strategy　variations,　suitable　for　optimizing　electromagnetic　mechanisms　with　diverse　parametric　forms.　(2)　The　improved　NSGA-Ⅱ　algorithm　judges　the　population　evolution　using　the　number　of　individuals　in　the　Pareto　frontier　and　selects　evolution　strategies　and　probability　settings　according　to　different　stages　of　population　evolution,　thereby　effectively　reducing　the　calculation　number　of　fitness　functions　and　enhancing　the　global　convergence.　(3)　Under　constant　flux　closed-loop　control,　the　electromagnetic　and　mechanical　inertia,　contact　bounces,　and　material　utilization　rate　are　taken　as　the　main　optimization　indicators.　The　designed　prototype　has　advantages　such　as　fast　response,　short　contact　bounce　time,　high　material　utilization　rate,　and　low　holding　power.　©　2024　China　Machine　Press.　All　rights　reserved.