Based on automatic weather station data, weather radar data, AWOS (Automated Weather Observation System) data collected at Ningbo Airport, and NCEP reanalysis data, the physical parameter field and radar echo characteristics of an isolated strong thunderstorm gale that occurred near Ningbo Airport on 22 July 2017 are analyzed. The results show the thunderstorm gale is mainly triggered by sea breeze front. The upper dry air, as well as warm and moist air near the surface, generates unstable atmospheric stratification of strong convective available potential energy and weak vertical wind shear. Cold pool and mesoscale thunderstorm high appear on the surface when the thunderstorm gale occurred. Rapid decline of top height of strong reflectivity, radial convergence at middle layer reaching 18 m·s-1,and velocity divergence at lower layer exceeding 25 m·s-1 are good indicators for thunderstorm gale warning.