Due to the limited functionalities of sensors and the unreliable wireless environment, traditional routing and relay strategies proposed for mobile ad hoc networks are not directly applicable to wireless sensor networks. In this paper, we present a multipath searching scheme by using a power-based parallel routing method suitable for wireless sensor networks. This work constructs noncoherent unitary signals and transmits them through cooperative multipath routes in wireless sensor network. We analyze the network performance by Markov chain model. Analysis and simulation prove that the new approach can improve the network performance in terms of throughput, end-to-end delay, drop probability and go through delay.