Stringent energy constraint is one of the most critical issues in wireless sensor networks. To address this issue, this paper proposes an ant colony-based energy-aware multipath routing algorithm. The algorithm, which considers the available power of nodes and the energy consumption of each path as the reliance of routing selection, utilizes the self-organization, self-adaptability and dynamic optimization capability of ant colony system to find the optimal path and multiple candidate paths from source nodes to sink nodes. It can avoid using up the energy of nodes on the optimal path and prolong the network lifetime while preserving network connectivity. Extensive simulations validate that the algorithm has a better performance in energy consumption and load-balancing with respect to traditional routing methods.