Aiming at problem that unknown transmitted power will affect on localization precision of wireless sensing node in wireless sensor networks（ WSNs）. A robust indoor localization optimized algorithm based on received signal strength indication（ RSSI） is proposed. According to the situation that transmitting power of anchor node in networks is unknown

transmitting power is expressed as an unknown parameter to participate in localization of target node. A complicated nonlinear non-convex localization problem is transformed into linear optimization problem using mathematical transformation and linear approximation method. Coordinate of target node is estimated by least squares method（ LSM）. The proposed algorithm is verified on computer simulation platform and real indoor environment and experimental results show that localization performance of the proposed is prior to traditional localization algorithm.