The change of the position of the mobile dual-polarization radar in the hail field observation, the fluctuation of the radar signal itself and the evolution of the precipitation system will cause the phenomenon that the measured parameters produce a large pulse. The system error calibration of was carried out by light rain method. At the same time, when SNR is greater than or equal to 10dB, the polarization parameters of radar are credible. The radial distribution profile of 3-point, 5-point,7-point,9-point and 11-point is analyzed, and it is considered that 7-point smoothing is adopted in this radar, which not only takes into account the reduction of parametric pulsation, but also avoids the loss of real information.