Based on the data from Doppler weather radar and regular observations，the characteristics of a thunderstorm gale with the maximum instantaneous wind over 12-13 grade occurring in the east of Shandong are analyzed. It is a thunderstorm gale case under the influence of upper northwestern current, and the lower vertical wind shear and high temperature lapse rate are favorable for the occurrence of it. The mesoscale boundary convergence line constantly triggers new convection cells and eventually the squall line structure comes into being. Features such as obvious radial divergence on surface layer (velocity difference≥35 m·s-1) or large radial velocity region (absolute value of velocity≥29 m·s-1), MARC (velocity difference≥30 m·s-1), strong mesoanticyclone at middle level (velocity difference≥31 m·s-1) and mesocyclone bottom height below 2 km are evident in the radial velocity chart for the thunderstorm gale stronger than storm in the process. These characteristics are of significant importance in disastrous gale detection and its early warning.