Abstract: An Airborne Wind Energy System (AWES) is a cutting-edge technology for the utilization of high-altitude wind energy. The vertical shear characteristics and fluctuation patterns of the high-altitude wind field have a significant influence on the operational stability of these systems. This study utilizes ERA5 reanalysis data from 2000 to 2025 and one year of in-situ measurements to investigate wind resource characteristics from ground level up to an altitude of 3000 m, including wind profile characteristics, the probability of vertical negative shear, and wind speed fluctuation patterns. The results indicate that wind speed profiles at different cumulative probabilities exhibit a consistent proportional relationship, enabling the estimation of wind speeds at various cumulative probabilities based on the time-averaged wind speed. Negative shear events, where wind speeds at higher altitudes are lower than those at lower altitudes, occur frequently, with the highest probability observed within the wind speed range of 4~8 m/s and the altitude range of 400~1000 m. The fluctuations of the 5-minute averaged wind speed generally conform to a normal distribution. The standard deviation of the wind speed fluctuation amplitude ranges from 0.8 to 0.9 m/s with varying height, while the standard deviation of the wind direction fluctuation amplitude ranges from 10° to 20°, decreasing with increasing wind speed and height. These results can provide support for the design and operational strategy formulation of high-altitude wind power generation systems.