The increasing application of WSN (Wireless Sensor Network) brings forward higher and higher requirements on the security of the network.The Sybil is one of the multitudinous security attacks that WSN has to face now and is one of the most ruinous.Based on the analysis of its attacking principle, a type of dispersing guarding algorithm linked with network localization was proposed.The algorithm was used for the measurement of the consistency and the calculation of two methods for the detection of attack nodes, which is different from the traditional centralized guarding mode.The emulation of the algorithm and the experiment results indicate that the algorithm has very good pertinence and robustness against Sybil attack.