Abstract: Disclosed are an optimization method and apparatus for an Interferometric Synthetic Aperture Radar (InSAR) time-series phase. The optimization method includes: obtaining a time-series SAR data set, and performing registration and L-looks processing on the time-series SAR data set to obtain an L-looks intensity data set and an interferometric data set respectively; taking the L-looks intensity data set as a reference, obtaining a preset digital elevation model (DEM) and a preset land cover image, performing registration and geocoding on the preset DEM to obtain a digital elevation in a SAR image coordinate system, and performing registration and geocoding on the preset land cover image to obtain a land cover image in the SAR image coordinate system; performing a differential operation on the interferometric data set to obtain a differential interferometric data set; and estimating a covariance matrix at each spatial pixel position, and estimating and obtaining an optimized time-series phase.