Energy constraint has become the major challenge in designing wireless sensor networks. Network lifetime is considered the most substantial metric in these networks. The routing technique is one of the best choices for maintaining a network lifetime. This paper demonstrates the implementation of the new methodology of routing in WSN using Firefly swarm intelligence. Energy consumption is the dominant issue in wireless sensor network routing. For network cutoff avoidance while maximizing net lifetime, energy exhaustion must be balanced. Balancing energy consumption is the key feature for the rising net lifetime of WSNs. This routing technique involves the determination of the optimal route from the node toward the sink to make energy exhaustion balance in the network and at the same time maximize network throughput and lifetime. The proposed technique show that it is better than other some routing techniques like Dijkstra routing, Fuzzy routing, and ant colony (ACO) routing technique. Results demonstrate that the proposed routing technique has beat the three routing techniques in throughput and extend net lifetime.