Site selection and task allocation of UAV (unmanned aerial vehicle) freight take-off and landing points at the leading end of the logistics chain in the complex environment of mountainous areas were studied. First of all, aiming at minmum cost of construction and maximum satisfaction of transportation, the performance of UAV and no-fly airspace were considered, then with multiple constraints and objective functions, the model of site selection and task allocation was constructed. The combinatorial algorithms of genetic and simulated annealing algorithm was adopted. First, the initial feasible solution adopted in annealing algorithm was obtained as optimal feasible solution by the genetic algorithm. What is shown is that the expected effect is achieved by the constructed multi-constraint model, and excellent applicability is shown when the algorithm is adopted to such problems.