Integrated　defense　against　earthquake　disaster　is　an　urgent　problem.　In　this　paper,　the　basic　principle　of　urban　multi-lines　for　seismic　defense　was　proposed.　The　basic　theory　of　defense　periphery　for　urban　earthquake　disaster　was　established.　The　exchange　rate　between　periphery　groups　was　regard　as　control　variable,　and　the　Lotka-Volterra　model　was　introduced　into　defense　periphery　system.　The　evolution　model　of　urban　multi-lines　for　earthquake　disaster　defense　was　set　up,　which　explained　the　competition　and　collaboration　dynamic　mechanism　of　urban　multi-lines　for　seismic　defense.　The　order　parameters　of　multi-lines　defense　system　were　selected　according　to　synergy　principle.　The　co-evolution　measurement　model　of　urban　multi-lines　for　defensing　earthquake　was　established,　and　it　was　applied　to　Nantong　city　earthquake　disaster　integrated　defense　system.　The　result　shows　that　competition　alienation　characteristics　of　defense　system　arise,　and　system　coordination　degree　is　reduced　to　0.62.　The　system　is　restored　to　the　previous　level　of　coordination　degree,　and　it　is　developing　towards　coordinated　direction　by　adjusting　the　input　proportion　of　multi-lines　for　seismic　defense.