Abstract: Interferometric synthetic aperture radar (InSAR) technology characterized by high monitoring precision, large scale and continuous spatial coverage, has become a powerful means to solve the problems of deformation monitoring in water conservancy projects. To circumvent the difficulties of InSAR time series analysis in deformation monitoring of reservoirs, a systematic research of methodologies and applications is carried out in this paper, considering the complexity and particularity of the application environment. Results from the application in the Guangnan Reservoir reveal that high-precision deformation time series can be extracted, which verifies that it is effective in deformation monitoring of reservoirs through InSAR time series analysis. Time series InSAR technique has great potential for reservoir safety survey and retrospect of deformation history.