Polarization and micro-Doppler signatures are widely used for target detection and recognition in harsh sensing environments. However, accurately estimating polarization scattering matrices and Doppler frequencies of scattering centers remains challenging. This paper incorporates the multi-channel spectrum interpolation with the CLEAN algorithm. The proposed algorithm can estimate the Doppler frequencies and scattering matrices of target scattering centers from fully-polarized data with high precision. Compared with the traditional detection-after-imaging workflow, the proposed method takes an iterative suppression technique, which improves the estimation accuracy and reduces detection time. The effectiveness of the proposed method is verified based on the simulation and actual radar data. The estimation accuracy measured by polarized similarity is 99.9%, and the normalized root mean squared error of the estimated Doppler frequency is 4.8% in simulation.