The present invention provides a metadata storage system and a management method for a cluster file system. The metadata of the cluster file system is stored by using a DRAM+SSD+HDD three-tier architecture, and the metadata is written sequentially into a metadata buffer in the DRAM based on write-in time. When a metadata buffer fully written, it is written back into the SSD sequentially to form a new metadata storage unit, and corresponding metadata index information in a header structure thereof is stored into the DRAM in a form of a metadata index unit.