Although traditional centroid localization algorithm is simple and low-cost range-free localization method

its positioning precision is inadequate and remains to improve. In order to solve this problem

an improved centroid localization algorithm is proposed to enhance the traditional centroid method by optimization of beacon nodes and utilization of the received signal strength indication（ RSSI） data. This revised method not only reduces localization error

but also overcomes shortcomings of traditional approach larger communication radius

and low positioning precision. Effectiveness and realibility of the algorithm is validated by MATLAB Simulation.