A metadata management method dividing directory path attribute from directory object is proposed, which extends the present object storage architecture. This method avoids efficiently the large-scale metadata migration according to the updating directory attributes, improves the cache utilization and hit rate by reducing the overlap cache of prefix directory, reduces the disks I/O demands by reducing the overhead of traversing the directory path and exploiting directory locality, and avoids overloading a single metadata server by dynamic load balancing. Experimental results demonstrate that this method has obvious advantages in improving the throughput, scalability, balancing metadata distribution, and in reducing the metadata migration.