There are shortcomings in traditional anti-theft technology which can not satisfy a user’s demand.The common ways of anti-theft are limited in wireless sensor networks.On the topic of the shadowing effect in wireless communication,this paper introduces a anti-theft technology based on wireless sensor networks.System can check intrusion by analyzing received signal strengths.This paper establishes a framework of anti-theft system and studies the key technologies.By defining the graph model in anti-theft system,the agent distribution problem is abstracted into edges partitioned by vertices problem.B-EPV algorithm is proposed for obtaining the optimal solution.Blade algorithm is designed for solving k-mode set problem to get steady status of link.This paper constructs experimental environment with real motes and verifies the performance of the system.The result shows low false positives and false negatives in the system.