By using the detection products of X-band dual-polarization radar of Fang shan and S-band weather radar Beijing Observatory, a comparative analysis of 15 severe convective weather processes in Beijing in the summer of 2018 was carried out, in order to explore the data value of new detection equipment. The results show that, compared with conventional weather radar, dual-polarization radar has obvious advantages in particle identification and has become a powerful means of weather forecast and warning such as hail. In hail recognition, the differential reflectivity factor (ZDR ) and correlation coefficient (ρhv ) of x-band dual-polarization radar are two important polarization quantities, ZDR which is small, closes to 0 and sometimes negative. ρhv is less than 0.9. In terms of heavy precipitation identification, large value of ZDR and differential propagation phase shift rate (KDP ) can better indicate precipitation with high rainfall intensity. When the 5-minute rainfall is close to 10mm, ZDR is usually above 5dB, KDP is above 8°/km, and ρhv is above 0.95 at low elevation. According to the comparative analysis of the two radars, the reflectivity factor intensity (R) and the vertical accumulation liquid water content (VIL) are stronger than SA weather radar. In addition, due to the short wavelength of X-band radar, the detection beam of a single radar will have a relatively serious electromagnetic attenuation when passing through the strong precipitation area, resulting in the weak intensity of precipitation echo behind the heavy precipitation, which seriously affects the forecaster"s judgment of precipitation intensity and rainfall duration. Therefore, it is necessary to cooperate with SA weather radar or use multiple X-band radars to network for the monitoring and analysis of heavy rainfall.