Wake vortex field formed in the process of flight is an important factor exerting an influence on the flight safety. In order to study the impact of wake vortex on the aircraft below at altitudes above 12,500 m, a physical model of aircraft wake vortex is established by a fast simulation method of wake vortex, and the sinking height of wake vortices at different flight altitudes is also calculated by Monte Carlo simulation. The difference in the sinking height of vortex core at high altitude and midlow altitude is analyzed. Then, the sinking height of highaltitude wake vortices are calculated under condition of different aircraft weights and atmospheric turbulence intensities. The result shows that compared with those in mediumand lowaltitudes, wake vortices in highaltitudes have larger sinking height on an average increment of 42.4~49.7 m. Reducing the aircraft weight can reduce the vertical impact range of the highaltitude wake vortex. After the atmospheric turbulence intensity exceeds 1.2×10-4 m2/s3, the sinking height of highaltitude wake vortex core changes slowly. These results give a reference to some lights on the reduction of vertical separation of highaltitude wake vortex.