In　this　paper,　the　cross-layer　optimal　design　of　multihop　ad　hoc　network　employing　full-duplex　cognitive　radios　(CRs)　is　investigated.　Firstly,　the　analytical　expressions　of　cooperative　spectrum　sensing　performance　for　multihop　CR　networks　over　composite　fading　channels　are　derived.　Then,　the　opportunistic　throughput　and　transmit　power　of　CRs　are　presented　based　on　the　derivation　of　false　alarm　and　missed　detection　probability.　Finally,　a　multiobjective　optimization　model　is　proposed　to　maximize　the　opportunistic　throughputs　and　minimize　the　transmitting　power.　Simulation　results　indicate　that　Pareto　optimal　solution　of　sensing　duration,　decision　threshold,　and　transmit　power　can　be　achieved　by　cross-layer　multiobjective　optimization,　it　can　balance　the　conflicts　between　different　objective　functions　and　reap　the　acceptable　outcomes　for　multihop　CR　network.