We study multi-path reliable routing in wireless sensor networks. When data is transmitting from the source node to the destination node, once forward nodes conflict or failures the data cannot transmit as usual. Data missing can cause a serious impact on the network. Therefore, it is worth investigating the reliability of routing protocols. Aiming at data missing caused by nodes confliction and failures, this paper starts with proposing a novel transfer relationship of two paths by a bridge. It is a notion used to react how the data is transmitted from one path to another path. We then formulate the optimal routing based on the transfer relationship by considering the effect of wireless interference as a bipartite graph model. Through the bipartite graph model, we can calculate the interference between two paths easily. In addition, we propose a strategy to deal with congestion and failures. The real test-bed experimental and simulation results show that the proposed algorithms can deal with network congestion and improve the reliability of transmission significantly.