To deal with the problems that the routing algorithm based on game theory for network congestion control (GTNCC) in low power and lossy networks cannot make the network topology optimal by only considering the wireless link quality during the process of routing construction and it cannot mitigate the network congestion quickly and efficiently through the child of the congested node determining whether to switch its parent during the process of congestion control, a routing protocol which adopts a centralized network congestion control based on multimetrics combination (CNCCMC) is proposed. Firstly, it takes into account of the metrics such as the residual energy of node, buffer occupancy rate, wireless link quality and the current number of subnodes for relay node in the process of routing construction to reduce the network congestion probability. Secondly, the child nodes are switched in a centralized way based on the result of traffic analysis and judgment by the congested node when network congestion is detected. Finally, a “pingpong effect” avoidance mechanism is proposed in the process of network congestion mitigation. The theoretical analysis and simulation results demonstrate that, compared with GTNCC routing algorithm, the performance of CNCCMC routing protocol in terms of the network congestion probability, the average network lifetime and the network throughput are improved significantly.