In order to meet the requirements of multi-target reconnaissance tasks undertaken by UAVs,a UAV mission assignment and path planning optimization method based on the improved A* algorithm is proposed.Firstly,in the Geographic Information System (GIS),the threat area is marked,and the planning area is confirmed.Secondly,the route range matrix is estimated based on the improved A* algorithm,and then the mission assignment result is obtained by using the model of Travelling Salesman Problem (TSP) and the genetic algorithm.Thirdly,according to the multi-target sequential mission assignment result,the path optimization is realized based on the improved A* algorithm,and the path smoothing is implemented by using the method of cubic B-spline curve.Finally,according to the variation of threat areas and mission objectives,the local dynamic programming space is determined,and the dynamic assignment of local missions and the dynamic planning of local path are implemented.A UAV mission planning software is developed,and the experiments have verified the effectiveness of the proposed method.