The use of mobile Unmanned Aerial Vehicle(DAV) to collect data from Wireless Sensor Networks(WSNs) has attracted great attention recently. It is often necessary to relate the stream of sensed data to the deployed location of the data producing sensor nodes. Therefore, UAV-based Robust Node Localization(UAV-NL) algorithm is proposed. In UAV-NL algorithm, the location of UAV is unknown. Each sensor node receives beacon packets transmitted by the UAV at random positions and records an Received Signal Strength Indicator(RSSI) vector. The norm distance of two RSSI vectors, which is theoretically proved to be linearly related to the distance between two nodes, is used for ranging. Distance calculation method is theoretically derived by using RSSI measurements. Location of node is estimated by Semi-Definite Programming(SDP) algorithm. Extensive simulations in different environments validate high localization accuracy of the proposed algorithm even under noisy channel conditions.