Wireless　sensor　and　actuator　networks　(WSANs),　as　the　promising　technologies　to　realize　efficient　and　energy-saving　control,　recently　have　been　one　of　the　main　research　focuses　in　academic　fields　as　well　as　in　control　applications.　In　this　paper,　considering　the　network-induced　delays,　the　joint　design　of　optimal　control　strategy　and　power　consumption　for　WSANs　is　addressed.　First,　the　WSAN　system　with　multiple　transmission　paths　is　modeled　as　a　linear　system　and　the　joint　optimization　problem　is　formulated　by　using　a　quadratic　cost　function.　Then,　a　two-step　control　scheme　is　presented　to　realize　the　joint　design　of　control　law　and　power　consumption.　In　particular,　the　optimal　control　strategy　for　each　given　path　is　iteratively　derived,　and　then　the　optimal　transmission　path　is　selected　with　the　minimum　system　cost.　Finally,　numerical　simulations　in　both　generic　control　systems　and　power　grid　systems　demonstrate　the　effectiveness　of　the　proposed　control　scheme.