Abstract: Data aggregation plays an important role in wireless sensor networks energy-efficient policy.The time control of data aggregation is one of the key issues，because it directly affects the accuracy of the data aggregation and delay.Data aggregation model is described by Poisson process and probability of data aggregation time is deducted.In order to meet certain requirements of the probability and data，a way to get data aggregation time control is addressed.Simulation shows that the theoretical analysis and simulation results are consistent.The conclusion provides a new idea to analyze data aggregation time control.

摘要： 数据聚合是无线传感器网络实现节能的一种重要技术。数据聚合的时机直接影响到数据聚合的准确度和延时，是数据聚合的关键问题之一。建立基于泊松过程的数据聚合模型，分析数据聚合时机的概率特征，提出满足一定概率要求和信息数要求的条件下，数据聚合时机的求解方法。仿真表明，理论分析和模拟实验结果基本相符。该结论为数据聚合时机的分析提供新的思路。