Abstract: By the stepped frequency-continuous wave technology,synthetic aperture radar and interferometric techniques,combining integrated ground-based SAR,can achieve high-precision monitoring of static and dynamic targets on the ground.This paper describes the dynamic deflection test carried out by the IBIS in the Wuhan Yangluo Yangtze River Bridge,and GPS measurements were compared.The results show that the ground-based SAR can not only fine to measure the dynamic changes in the bridge deflection,high accuracy;and can truly reflect the structure of the dynamic deformation characteristics,its high sampling rate feature provides a new means of technology for the bridge vertical bending test.