Aiming at air-ground collaboration of Unmanned Aerial Vehicle (UAV) with Unattended Ground Sensor (UGS) for target tracking, this paper proposes a searching and tracking method for moving targets based on local search trees in the traffic road network environment.In this method, the UAV is in close communication with an UGS to obtain the time information of the target passing through the node.Based on the information, the target motion speed is estimated and the subsequent target position is predicted.The path of UAV in target tracking is optimized through local recursive search.For the decision-making of sensor node accessing order with incomplete information in the tracking process, two kinds of node selection evaluation mechanisms are designed and analysis is made to their effects.Simulation results show that this method can capture targets with a higher probability when the targets moving path and speed change greatly.