Abstract: Using the data from conventional meteorological observations,intensive automatic weather stations,radiosonde,airport automated weather observing system,Doppler radar and so on,the environmental conditions and influencing systems for a thunderstorm gale in Hefei airport and its surrounding areas on May 14,2017,were analyzed.Focused on Doppler radar data,the causes for the formation of the thunderstorm process were discussed.Results can be described as followings.Two convective storms in the northwestern part of the airport were merged at the levels of 3-6 km.A factor nucleus with strong reflectivity was formed at the level of 5 km.It quickly dropped to 4 km within 10 minutes.A strong cold pool was formed on the ground when the downdraft within the storm sinks.Its rapid movement led to the formation of strong winds at the airport.The initial cause of the downdraft formation is due to the drop and drag effects of the precipitation particles.The effect of inhalation,increasing of negative buoyancy between hydrate and the environment,downward momentum transmission,and the compensatory airflow are the important reasons for the downdraft formation.The gale belt in the southwestern part of the airport was resulted by the transiting of a thunderstorm outflow boundary.The extinction of super-refraction is a sign of cold air intrusion in the boundary layer.The continued cold air replenishment at the back of the storm and the continuous updraft in front of the storm maintains a steady vertical circulation.The continuous redeeming downdraft causes the gale in the eastern part of the airport to last for a long time.