Differential synthetic aperture radar (SAR) tomography reconstructs the backscattering coefficient and line-of-sight deformation rate of the target by multi-pass data. We combine the full-polarization and differential SAR tomography. Aiming at urban building imaging elevation sparseness and the same signal sparse support set in full-polarization data inversion, a solution model combined with sparse constraints and group sparse constraints is solved by threshold iterative method based on hierarchical sparseness. The simulation and semi-simulation experiment based on BioSAR data are done to verify the results. The experiment shows compared with the monopole the reconstruction results the full-polarization differential SAR tomography method improve the accuracy of elevation and has better robustness. When the signal-to-noise ratio is 10 dB, it can recover the elevation information and deformation rate better than the single-polarization differential SAR tomography method.