In order to monitor the regional weather in the central region of Inner Mongolia in real time, the radar mosaic obtained from the base reflectivity products of the new generation of weather radar and the Plane Position Indicator(PPI) echoes from 713 radar is studied. Firstly, the storage structure of the two types of echo data is analyzed in detail. And then, a translation algorithm is developed to turn both types of data into two-dimensional matrices, and the drawing mode of converting both types of files to the raster files under the rectangular coordinate system is used, and implemented by ArcGIS Engine. Finally, the paper considers the radar mosaic obtained from the two types of echo images, and has designed and developed the regional echo mosaic platform to merge the four radar echo images in real time according to the user's requirements. The application of this system produces very good results in the weather bureau of Baotou City, and it is shown that this platform can monitor the regional weather in the central region of Inner Mongolia in real time, to supply supplementary decision information for weathermen to make weather forecast and warning.