Solar-powered　nodes　have　been　employed　in　farmland　wireless　sensor　networks　to　prolong　the　lifetime,　which　can　increase　the　cost　at　the　same　time.　The　energy　acquisition　mode　of　solar-powered　node　is　intermittent　and　nonlinear,　because　it　is　easy　to　be　influenced　by　the　external　factors.　In　this　paper,　a　fuzzy　prediction　method　of　the　solar　energy　using　the　weather　forecast　is　proposed,　and　then　a　fuzzy　selection　method　to　distinguish　the　different　types　of　nodes　is　proposed.　Simulation　results　show　that　the　proposed　method　can　improve　the　network　throughput　and　reduce　the　energy　consumption　of　nodes.