The article presents the results of theoretical studies to establish the nature of the distribution and determine the speed of the air flow formed along a moving high-speed passenger train. In studies, to preserve the geometric similarity, a high-speed train is considered in the form of a bar (or plate) of rectangular cross-section moving in three-dimensional space. To simplify the problem, the movement of a high-speed train at a speed of 160-250 km / h in flat terrain, when the height of the embankment is constant, is considered. Assuming that when a high-speed train moves, a turbulent wake is formed, the problem is solved for a turbulent flow using the method of the equivalent heat conduction problem. An equation for the distribution of the layer and along a moving high-speed passenger train is obtained. The results obtained at this stage made it possible to establish the size of the boundary layer and the nature of the change in the distribution of the air flow velocity in its aisles; investigate the impact of secondary air currents generated by high-speed passenger trains on the environment along the high-speed railway.