The weather radar 3D mosaic data are useful in many ways. And today, th e CINRAD observational data are able to mainly real time transfer to the regiona l centre. To make full use of the radar observation network, the CINRAD 3D digita l mosaic system is developed based on recent related research results. The syste m focuses on data processing in the background, with simple and convenient con trolling interface. Multithreaded programming techniques improve the efficien cy of data processing, modularized management of multithreads is easy to expand new algorithm modules, and mixedlanguage programming technology shortened the p eriod of applying results of scientific research in operation. The s ystem works efficiently on PC, generating regional threedimensional mosaic reflectivit y and some derived products with high spatial and time resolution