Abstract: In a multi-hop wireless sensor network (WSN)，the sensors closest to the sink tend to deplete their energy faster than other sensors,which is known as an energy hole around the sink. hhis paper employed the unit deployment cost of the network life, network efficiency, which is more reasonable and is our optimization goal. It is a challenging research that how to avoid energy hole and maximize network efficiency by effective node deployment when we just know the scale of the network and the sense radius of the node. hhis paper gave an algorithm of effective node deployment and worked out the best number of work node, the best deployment approach of relay node, the optimal node transmission distance. hhe algorithm not only be able to avoid energy hole, and also effectively improve network efficiency, compared with the uniform deployment algorithm and the non-uniform deployment algorithm. Therefore, the algorithm is of great significance for the application of constructing low-cost wireless sensor networks.

Key words: Wireless sensor networks, Avoid energy hole, Network efficiency, Multi-objective optimization problem,Sensor placement