The invention discloses a wireless sensor network topology discovery method and device. The wireless sensor network topology discovery method comprises the steps that a broadcast first topology request is received, wherein the first topology request includes control node addresses and topological serial numbers; local neighbor lists and the topological serial numbers are packaged to topological restoration data, and the topological restoration data is sent to corresponding control nodes according to the control node addresses; a second topology request is generated according to the control node addresses and the topological serial numbers, and the second topology request is broadcast. The method processes the neighbor lists of sensing nodes in a unified mode through the control nodes, accordingly whole-network topology can be effectively determined, and an optimal routing path can be determined through the sensing nodes according to the whole-network topology. The sensing nodes only need to receive the whole-network topology sent by the control nodes without local execution of a routing algorithm, the calculation quantity of local nodes is reduced, and the processing efficiency of the local nodes can be improved.