This paper optimizes the classical routing protocol-AODV(Ad Hoc on Demand Distance Vector)and introduces an improved routing protocol-BCOAODV. The protocol considers the value of backup paths and the value of routing overhead as important performance index, it can effectively balance the network traffic and fix the link by backup paths when interruption happens. Simulation results show that, in most cases, compared with the AODV, BCOAODV has better perfomence.