Abstract: There is no direct solar illumination in the permanently shadowed regions (PSR) at the polar region of the Moon. Detecting water-ice in PSR is a significant scientific question. Until now, no spacecraft has landed in PSR. Chang’E-7 mission plans a rover landing at the solar illuminated region near PSR. A mini-flyer carried by the lander will fly to the PSR to collect regolith samples for analysis. Selection of landing site and sampling site is critical for the mission. The Polarization Synthetic Aperture Radar (Pol-SAR) onboard Chang’E-7 satellite can evaluate the roughness of lunar surface, the landing site, the sampling site and the flying trajectory with the assistance of high-resolution digital elevation model. By comparing the SAR data acquired by the Mini-RF onboard Lunar Reconnaissance Orbiter with the optical images at the solar illuminated region, we analyze the role that Pol-SAR play in selecting the flat landing site and sampling site. Regions near Hyginus crater and the landing site of Chang’E-4 mission are taken as examples. HRNet is used in lunar SAR image segmentation. The application of neutral network in lunar SAR image segmentation is discussed. Craters Shoemaker and Shackleton at lunar south pole are analyzed to find flat surface in PSR as potential landing sites. This paper provides a reliable reference for SAR detection in Chang’E-7 mission.