A　multi-function　rescue　attachment　with　tonging,　shearing,　and　grabbing　capabilities　was　developed　to　improve　the　rescue　operation　efficiency　and　save　the　time　of　switching　different　attachments　during　rescue　operations.　The　weighted　least　squares　support　vector　machine　(WLS-SVM)　response　surface　method　was　improved　to　establish　the　approximate　model　of　grabbing　mechanism.　The　maximum　equivalent　stress,　the　maximum　deformation　and　the　mass　were　proposed　to　evaluate　the　performance　of　mechanism　based　on　the　approximate　model,　then　the　non-dominated　sorting　genetic　algorithm　(NSGA-II)　was　introduced　for　multi-objective　optimization.　To　improve　the　population　diversity　and　the　search　ability　of　NSGA-Ⅱ,　the　elite　strategy,　the　crossover　operator　and　the　mutation　operator　were　improved.　Additionally,　the　NSGA-II　and　the　improved　algorithm　were　used　for　multi-objective　optimization　of　grabbing　mechanism.　Finally,　the　multi-dimensional　Pareto　front　was　visualized　in　a　two-dimensional　plane　by　the　radial　coordinate　visualization　method,　and　the　most　satisfied　solutions　were　selected.　The　comparison　shows　that　the　Pareto　solution　distribution　of　the　improved　algorithm　can　be　distributed　more　uniformly,　and　the　target　values　of　the　most　satisfied　solution　can　be　smaller.　Particularly,　the　lightweight　design　can　be　effectively　carried　on　in　a　condition　that　ensures　the　reliability　of　the　grabbing　mechanism.　©　2018,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.