Mobile Ad Hoc network features itself as self-organizing，multi-hop wireless network and this give rise to challenges for the network design，including high network energy efficiency consideration because typical applications of Mobile Ad Hoc network often assume limited power resource of network participants. At the beginning，current research status of energy-efficient technique in Mobile Ad Hoc network is summarized. Then based on the analysis of Energy-consume Model for data transmission in wireless network，principles for the energy-efficient design for wireless Ad Hoc network both in Media Access Control(MAC) layer and network layer are introduced. Finally，Further improvement on energy saving should consider cross-layer design.