In August 2019, the GLC-12A-type mobile X-band dual-polarization weather radar, developed by Fourteen Research Institute of China Electronics Technology Group, was used to conduct field tests in Dafeng, Jiangsu Province. In this paper, the data quality of the mobile X-band dual-polarization radar was analyzed by using the field observation data of this radar and the CINRAD/SA radar in Yancheng, and the data of six rainfall stations in Jiangsu Province. The results show that the attenuation of the radar after passing through the rain area is related to the distance. For the same precipitation process, the farther the distance, the greater the attenuation. In order to reduce the observation error caused by attenuation, the difference reflectivity Zdr and correlation coefficient ρhv(0) are corrected by signal-to-noise ratio (SNR) to improve the data quality for ground or biological clutter removing. Then the differential propagation phase shift rate Kdp or differential propagation phase dp after quality control was used to express the total bidirectional reflectivity factor attenuation correction at the distance of R in rain. At last, data analysis shows that the data quality of the revised mobile X-band dual-polarization radar has been improved.