Abstract: With the continuous advancement of urbanization and the increasing population density, the economic losses caused by disasters such as urban waterlogging are rising year by year. A scientific and effective radar quantitative precipitation estimation (QPE) product is of great significance for monitoring extreme precipitation and disaster prevention and mitigation. This paper utilizes data from one S-band dual-polarization radar and six X-band dual-polarization phased array radars in Jiaxing to develop S-band and X-band radar QPE products for the region. After preprocessing the radar observation data, including the removal of non-meteorological echoes and quality control of the differential propagation phase, the effective minimum hybrid elevation for each radar is calculated. Then, estimation of rain rate with single radar observations is achieved using raindrop size distribution parameters provided by Global Precipitation Measurement Dual-frequency Precipitation Radar （GPM-DPR）. Finally, mosaicking of rain rate for multi radars is achieved, forming a gridded QPE product with temporal resolution of 1 min and spatial resolution of 50 m. To verify the accuracy of the proposed method, two heavy precipitation events on September 10 and 16, 2024, in the Jiaxing area are selected to evaluate the radar QPE products. The evaluated products include the original X-band QPE product of Jiaxing, the X-band, S-band, and mosaicking products developed in this paper. The results show that the QPE products in this paper are better than the original X-band product in terms of accuracy and stability, with the mosaicking product exhibiting the best estimation result. For localized heavy rainfall, the mosaicking product can accurately reflect the precipitation distribution across various towns, contributing to early warning release.