In order to solve problem of unbalanced energy consumption of wireless sensor networks（ WSNs）

and short lifetime of networks

on the basis of studies on several existing routing protocol based on LEACH protocol

propose an inter-cluster multi-hop routing protocol based on LEACH protocol. The protocol introduces energy factor

density factor and distance factor to correct threshold function for LEACH protocol and optimize cluster head set combined with Cuckoo Search

and also propose a new routing mechanism

cluster head nodes communicate with Sink node by multi-hop mode. Simulation results show that

compared with LEACH protocol

the new proposed protocol can balance effectively energy consumption of network nodes

and prolong network lifecycle.