To reduce the energy consumption of wireless sensor network nodes and prolong the lifetime of the network, the optimal location of graph theory is applied to the clustering routing protocol. In order to reduce and balance the energy consumption in the cluster, the cluster head election is carried out according to the residual energy of the nodes and the center theory algorithm of graph theory. According to the energy of the next hop cluster head, Dijkstra algorithm is used to build the best route and determine the best hop number to save energy consumption of data transmission and balance the whole network energy consumption. The algorithm is applied to the airport single light monitoring system, and the simulation results show that compared with AL-CAME and ECOMP, the algorithm based on graph theory has the least network overhead, the residual energy value is far greater than the other two algorithms, the distribution of network energy consumption is more balanced, and the life cycle of the network is effectively extended.