On　the　base　of　explaining　Multi-Objective　Optimization　Problems　(MOOP)　and　Collaborative　Optimization　Techniques　(COT),　this　paper　puts　forward　an　original　and　efficient　approach-Collaborative　Optimization　Technique　for　Multi-Objective　Optimization　Problems　(COTMOOP)-which　combines　Collaborative　Optimization　(CO)　techniques　and　Evolutionary　Algorithms　(EAs).　It　has　been　developed　so　as　to　facilitate　the　organizations　and　increase　the　performances　of　complex　coupling　systems　design　and　optimization.　The　newly　method　has　been　succeeded　in　applying　to　the　design　and　optimization　of　excavator　boom　mechanism　that　is　a　complex　coupling　system.　The　optimal　solutions　can　prove　that　the　approach　is　efficient　and　practical.