The lunar penetrating radar(LPR) onboard the Chang E-4 (CE-4) probe provides a unique opportunity to map the shallow lunar structures on the far side of the Moon with high resolution. However, due to the timed-triggered acquisition mode, the LPR kept acquiring data when the rover was turning and stopped. In this study, we innovatively extracted the polarimetric scattering matrix from the data acquired at different orientations at the same location during rover turning. Subsequently, we quantify the regolith maturity within 24 m depth based on the Freeman decomposition results. The results provide new insights of the evolution of lunar regolith at landing site.