Extenicsisanewlydevelopedinterdisciplinarysubjectcombiningmathematics,philosophyandengineering.Itprovidesusefulformalizedqualitativetoolsandquantitativetoolsforsolvingcontradictoryproblems.Inthispaper,extensiontheoryisintroducedbrieflyandtheprimaryapplicationsofthistheoryandmethodsinbionicengineeringresearcharediscussed.Theextensionmodelofbiologicalcouplingfunctionalsystemisestablished.Inordertoidentifytheprimaryandsecondarysequencingofcouplingelements,theExtensionAnalyticHierarchyProcess(EAHP)wasadoptedtoanalyzethecontributionofeachcouplingelementtothecouplingfunctionalsystem.Thus,theinfluenceweightfactorofeachcouplingelementcanbedetermined,soastoprovideanewapproachforsolvingprimaryandsecondarysequencingproblemofcouplingelementsinaquantitativeway,andfacilitatethesubsequentbioniccouplingstudy.
