Active queue management algorithm works at network routing node. It notifies terminal system control transmission rate in advance with discard or mark packet before buffer queue overflows, so as to avoid congestion. Aiming at characteristics of wireless sensor network (WSN) and based on introduction of traditional RED algorithm, the paper introduced H parameter to represent traffic similarity to original linear relationship between packet loss probability and average queue length to form the non-linear relationship related to self-similarity. Then a kind of improved RED algorithm of WSN oriented to self-similar traffic was proposed. The detail implementation flow was also provided. Simulation based on OPNET shows that the improved RED is superior to traditional RED algorithm in steady performance.