Coverage optimization is a fundamental issue for the operation and management of wireless sensor Network（WSN） .In this paper

we first simply introduced the components of sensor node

the technique of node orientation and the architecture of sensor network. Then the background of sensor coverage is given and the method and mathematical model of coverage redundant detection are described. And then coverage optimization based on energy efficiency and network connectivity is discussed. Followed the technology of coverage & control is emphatically considered and its key technique is predicted.