The invention discloses a flash-oriented fine-grained non-volatile caching system and a cache management method. The system comprises a volatile caching module arranged at a host end and used for caching read-write operation contents in a file system and performing management and allocation on a caching space of the volatile caching module in a coarse-grained manner, and a non-volatile caching module arranged at the host end and used for caching synchronous operation contents in the file system, performing management and allocation on a caching space of the non-volatile caching module in a fine-grained manner, and writing back contents of a replaced data page to a corresponding position of a solid-state disk when the data page is replaced, wherein the solid-state disk is arranged at a storage end and used for interacting with the volatile caching module to realize reading and write-back operations of a cached page in the volatile caching module. According to the system, the phenomenon of cached data loss caused by power failure or crash faults of the system is avoided, the system performance is improved, and the service life of a device is prolonged.