One of the aims to design the underwater acoustic sensor networks is to supply the reliable communications between nodes and minimize the energy consumption as well. According to the absorption loss of underwater acoustic signals in the ocean and the parameters of the components, parameter of sensor node and actual surroundings, it also states the methods of forming the energy consumption model of the underwater sensor networks in the structure of centralized topology and Multi-hop topology.Application of the relay in fact a waste of energy. In short-range communication, however adopt the centralized topology structure have high energy efficiency. In long-range communication application of Multi-hop topology and choose the suitable number of nodes have the high energy efficiency. At last, that result is validated by simulation.