Abstract: The National Meteorological Center has of ficially launched MICAPS4 system since 2013. The MICAPS4 system uses a client/server system architecture. On the one hand, a real-time forecasting system based on Big Data technology to solve the key technical problems in processing, storage, analysis and display of meteorological big data is established; On the other hand, several specialized forecast platforms to meet the needs of different complex forecasting business is built. Based on MICAPS4 basic framework, a number of professional client have been applied to promote in NMC and part of the province. Utilizing distributed storage and distributed computing technology, the MICAPS4 server system can hold hundreds of TBs meteorological real-time data, providing data service for hundreds of concurrent users. MICAPS4 server system be the first to transits all meteorological real-time data storage from file system to database, from centralized system to distributed system in China. Under the condition of massive meteorological data and concurrent access of many users, MICAPS4 server system shows high stability and excellent read-write performance, it reduces the system maintenance workload greatly, and improves data analysis and data storage access ef ficiency signi ficantly.