By using ADAS (ARPS Data Analysis System) and NCEP GFS data as the background field, an assimilation experiment is conducted on CB\\CC Doppler radar reflectivity in Northwest China, and by means of WRF (Weather Research and Forecasting Model), a weather process occurred around the Hetao region of Yellow River and Hebei Province is simulated. The contrast between the experiment results using different simulation schemes and the forecasting verification show that: (1) the introducing of the C Band radar reflectivity data is complementary in space with the S Band radar data, and the rainfall field and vertical structure information given by the complex cloud analysis scheme with satellite and surface observation data are closer to reality. (2) The scheme with C Band radar reflectivity assimilated is superior to the unassimilated for the simulation of the reflectivity echoes, but the simulated system is gradually ebbed because of the inadequate water supply, which is different from reality. (3) The contrast between different assimilation schemes with the real precipitation indicates that the assimilated reflectivities improved the short time precipitation forecast.