The performance assessment is required using simulation experiment platform no matter what kind of frame model and algorithm is utilized in wireless sensor network intrusion detection system, in which the packer traffic model is an important factor for assessing the performance of intrusion detection systems objectively and comprehensively. According to coverage degree of the sensed points within the surveillance area,a packet traffic model was proposed, which could be applied to wireless sensor network intrusion detection system by means of the simulation tool.The theoretical analysis was verified. Simulation results and practical application showed that the proposed packet traffic model built a data source model for the data traffic of wireless sensor network, according to the actual traffic load; it could assess the performance of wireless sensor network intrusion detection system with high accuracy and easy to analysis.