Abstract: High precision indoor localization is the basis of location based service in Internet of Thing. The received signal strength indicator (RSSI) values of bluetooth low energy (BLE) can be used to do analysis and computation in location system. Therefore, Gaussian sum filter-based indoor localization used bluetooth beacons (GSF-IL) is proposed in this paper. Considering the multipath fading and fluctuation of indoor environmental signals, the Gaussian sum filter (GSF) is used to process the RSSI measurement value, so that the RSSI value has non-Gaussian characteristics, and the Wasserstein distance (WD) is used to reduce the component number of the GSF model to a single Gaussian component. Simulation results show that the proposed GSF-IL algorithm can modify the original RSSI value and make use of the positioning accuracy.