Abstract: Ranging error results in inaccurate localization of nodes in wireless sensor networks. Focusing on the problem, this paper proposes a WSN node localization method based on the fruit fly optimization algorithm. In this method, the problem of node localization is transformed into a constrained optimization problem, In the process of solving, the dynamic step size mechanism is used to control the optimal range of fruit fly population. When the algorithm converges, in the vicinity of the optimal solution creates new fruit fly populations, Using the centroid algorithm locate the fruit fly population as the final node position.Simulation results show that the method has fast convergence speed, high positioning accuracy and strong error resistance.