Maintaining data indexes and query cache becomes the bottleneck of the database, especially in the context of frequently updated data. In order to reduce the burden of the database, a cache system for frequently updated data has been proposed in this paper. In the system, update statements are parsed firstly. Then updated data are saved as key-value pairs in the cache and they are synchronized into the database at idle time. Experimental results show that the proposed cache system cannot only accelerate the data updating rate, but also improve the data writing ability in maintaining indexes and consistency of cache data greatly.