The invention discloses a network-attached storage system including an interface module, a plurality of storage devices and a storage module. The interface module is configured to be attached to a network. The interface module is for receiving a transmission protocol information transmitted over the network, and processing the information into storage data and access instructions. The storage module is for receiving the storage data and the access instructions, and controlling, according to the access instructions, access of the storage data to the primary storage devices through a transmission interface.