The problem of data collection from nodes disconnected large-scale wireless sensor networks is considered. A solution is proposed using a mobile gateway based on UAVs. The article solves the task of building a UAV flight path for data collection to achieve certain objective functions: minimizing data collection time, maximizing network operation time. The task is solved in stages: formation and optimization of virtual network clusters, construction of the main UAV flight trajectory using a certain heuristic algorithm for finding the shortest path, adjustment of the main route using algorithms (heuristics) to achieve objective functions. Real-time admissible solutions are based on the application of a set of developed algorithms (heuristics) that consider the mutual arrangement of nodes, their battery power level and data volume. A simulation model has been developed to assess the effectiveness of algorithms for constructing a UAV flight trajectory for data collection. The results of simulation modeling demonstrate the possibility of reducing the UAV trajectory length by up to 30% and reducing the energy consumption of nodes by up to 15% compared to existing solutions.