In mobile ad hoc networks, nodes are usually powered by batteries with limited energy. To prolong the network life, the energy consumption of the routing task is crucial. In previous works, enormous topology control methods were given to support the energy-efficient routing, while the most of them are designed for static network. In this paper, we proposed a novel topology control scheme for mobile nodes. It is based on an adjustable structure, named the r-neighborhood graph. Simulation results show the proposed scheme can significantly improve the energy consumption especially in high mobility environment.