With　the　rapid　development　of　wireless　communication　technology,　the　newest　development　of　wireless　sensor　and　actuator　networks　(WSANs)　provides　significant　potential　applications　for　various　real-time　scenarios.　Currently,　extensive　research　activities　have　been　carried　out　in　the　field　of　efficient　resource　management　and　control　design.　However,　the　stability　of　the　controlled　plant　and　the　efficiency　of　network　resources　are　rarely　considered　collaboratively　in　existing　works.　In　this　paper,　in　order　to　enhance　the　control　stability　and　improve　the　power　consumption　efficiency　for　the　WSAN,　a　novel　three-step　optimization　algorithm　jointly　designing　the　control　strategy　and　transmission　path　routing　is　proposed　when　the　time　delay　is　considered.　First,　the　minimum　hop　routing　algorithm　is　used　to　obtain　the　set　of　candidate　transmission　paths.　Then,　the　optimal　control　signals　for　each　candidate　transmission　path　can　be　iteratively　derived　with　a　backward　recursion　method.　Finally,　the　best　transmission　path　is　determined　under　the　optimal　control　strategy　to　achieve　the　joint　optimization　design.　The　effectiveness　of　the　proposed　joint　optimization　algorithm　is　verified　by　the　simulations　of　the　application　in　the　power　grid　system.