In order to solve the maldistribution problem for wireless sensor network, topology control algorithm based-on regional assignment with switched-beam directional antennas, SRADTC is proposed. Through the number of the key neighbor nodes, the whole network can be divided into several sparse area and dense area. In sparse area, network topology is controlled by the minimum spanning tree algorithm. In dense area, network topology is controlled by the K-Neigh control topology algorithm. Pareto distribution node model will be built to compare the effectiveness between SRADTC and traditional topology control algorithms. Simulation results show that, under the precondition of ensuring the network connectivity, SRADTC improves the performance of network.