Coupling　model　with　a　few　parameters,　which　was　based　on　conditional　generalized　minimum　variance　method　and　blind　number　theory,　was　established　in　this　paper　to　evaluate　the　regional　foundation　subsidence　in　soft　soil　area.　Firstly,　the　most　critical　influences　were　filtered　by　conditional　generalized　minimum　variance　method.　Secondly,　the　relationship　between　key　factors　and　seismic　depression　were　calculated　according　quadratic　regression　model.　Finally,　possible　values　and　faith　degree　of　seismic　depression　were　obtained　by　blind　number　theory　to　evaluate　the　regional　foundation　settlement.　The　applicability　and　accuracy　of　the　model　were　proved　by　instance　analysis　and　the　results　showed　that　effect　was　good.　The　method　in　this　paper　provided　a　new　way　for　evaluating　the　regional　foundation　settlement.