Based on the S-band dual-polarization Doppler weather radar data of Jinan, Qingdao, and Yantai, combined with sounding and surface meteorological observation data, the key environmental physical parameters and polarization characteristics, such as the low-level severe hail area of the storm, three body scattering, and severe hail attenuation of the two severe convective weather processes that happened on 17 May and 1 June 2020 in Shandong are analyzed. The results are listed as follows. 1) The two severe convective weather processes both have large temperature difference and strong vertical wind shear, and the atmosphere is dry in the middle level. The stronger 0-6 km vertical wind shear, higher humidity in the lower level, and lower height of the wet bulb 0 ℃ layer are the key physical parameters for producing multiple supercell storms and very large hails in Shandong Peninsula on 17 May 2020. 2) There are moderate differential reflectivity (ZDR), reduced correlation coefficient (CC), and larger specific differential phase (KDP) in the low-level severe hail area of the storm in Chengyang on 17 May. ZDR ranges between 0.30 dB and 2.60 dB with an average of 1.50 dB, CC between 0.900 and 0.965 with an average of 0.931, and KDP between 2.0 (°)·km-1 and 6.3 (°)·km-1 with an average of 4.1 (°)·km-1. A small number of melting hail particles and large raindrops lead to moderate ZDR and larger KDP. 3) Smaller ZDR, reduced CC, and larger KDP are the polarization characteristics of the low-level severe hail area of the storm in Changqing on 1 June. ZDR ranges between -0.12 dB and 1.50 dB with an average of 0.68 dB, CC between 0.925 and 0.970 with an average of 0.950, and KDP between 4.0 (°)·km-1 and 7.6 (°)·km-1 with an average of 5.8 (°)·km-1. The high concentration of liquid raindrops and small melting hail particles lead to larger KDP. 4) The three-body scattering signature, side-lobe echo, attenuation, and nonuniform beam filling (NBF) can be used to identify hails. The attenuation is obvious on ZDR products, there are negative values in the longer radial distance behind the storm core, and the significant attenuation can be used as the criterion for very large hails. NBF merely presents obvious characteristics on CC products and CC is obviously smaller in the longer radial distance behind the storm core.