The reliability of wireless sensor networks is significant in certain applications, especially the reliable routing. Most existing routing protocols use multi-paths to improve routing reliability. However, multi-paths waste a large amount of energy to obtain redundancy. This is not an optimal option for sensor nodes with limited energy. In this paper, a novel clustering-based reliable multi-hop routing algorithm (CRMR) is proposed. The algorithm adopts a mechanism of multiple backup cluster heads efficiently to extend time of stable period of clusters and to decrease energy consumption for reconstructing clusters. The local reconstruction of clusters is addressed for improving coverage, maintaining connectivity, and extending the network lifetime. While the algorithm overcomes the randomicity of selecting cluster heads and ensures well proportioned clusters. Employing backup cluster heads and gateways can ensure reliability of routing and overcome disadvantages of most existing reliable routing protocols, which is to preserve multiple backup paths. The algorithm adopts query driving data transmission mode for finding routes and bypassing unavailable routing nodes for backtracking to ensure the speediness of data transmissions and the reliability. The simulation results show that the algorithm can achieve good performance on both routing reliability and energy consumption.