Abstract: In the process of routing for data fusion in the wireless sensor network(WSN),it is necessary to minimize energy consumption.Due to the selfishness of node for conserving energy,it is likely to make every node refuse to transmit others data and energy consumption unevenly.In this case,the performance and lifetime of WSN is restricted.Based on the coalition game theory,we give an approach for modeling the above problem.We adopt the characteristic function to describe the gain and cost from a coalition.Then,we design a greedy algorithm to search the sub-optimal coalition structure in a large-scale solution space,and conclude that the solution is acceptable with a scope of errors.Experimental results show that the proposed can be well used to prolong the WSN lifetime.