Software-defined sensor networks (SDSN) has appeared as a new networking paradigm that allows centralized management and control of networking devices programmably to increase network reliability. In this paper, we propose a joint routing and resource management algorithm that maximizes the system throughput for SDSN. We show that the formulated optimization problem can be proved convexifiable through re-parameterization and can be decomposed into two sub-problems by adopting Lagrangian decomposition approach. Therefore, the proposed joint routing and resource management algorithm(JRRC) can be implemented in two phases, where the routing is realized distributedly using the improved C-SPMR, and the resource management is done for SDSN nodes under the control of the central controller. Simulation results show that JRRC can effectively schedule resource to maximise the throughput based on the network state.