Aiming at problems that cluster head node election is unreasonable

which leads to nodes consume their power quickly and network lifetime decreasing in classical routing algorithm LEACH for WSNs

propose an improved LEACH-EC algorithm. The algorithm gives full consideration of other factors of surplus energy and connectivity of node

use the method to modify threshold and optimize cluster head election

so as to avoid the possibility of low energy and low connectivity nodes act as cluster heads. Simulation results show that the algorithm balances ratio of energy consumption of the overall network effectively and prolong the lifetime of node and network.