A content sharing method in a network storage system, the method comprising: receiving a shared content access request which carries an identity, ID, of a user sending shared content, an ID of a user receiving shared content, and a content identity, contentID, of a shared node, said node being a file or a directory; authenticating the user receiving shared content according to the ID of the user sending shared content, the ID of the user receiving shared content, and the contentID of the shared node; and providing shared content to the user receiving shared content according to the contentID of the shared node after the authentication succeeds; characterized in that the method further comprises: before receiving the shared content access request, organizing the nodes in a directory tree in the following way: allocating a contentID unique in the network storage system for each node in the system, wherein the contentID remains the same all the time; and associating the contentID with organization information of the node, wherein the organization information comprises a parentContentID of the node and a contentName of the node, wherein the associating is performed by assigning the organization information of the node to the contentID of the node, wherein the parentContentID is a contentID of a parent directory of a file in case the contentID identifies the file and the parentContentID is a contentID of a parent directory of a directory in case the contentID identifies the directory, wherein the contentName is a name of a content, wherein, when the node is a file, the organization information further comprises an ID of a physical entity corresponding to the node, wherein the ID of the physical entity corresponds to a lower layer storage path of the physical entity. receiving a shared content access request which carries an identity, ID, of a user sending shared content, an ID of a user receiving shared content, and a content identity, contentID, of a shared node, said node being a file or a directory; authenticating the user receiving shared content according to the ID of the user sending shared content, the ID of the user receiving shared content, and the contentID of the shared node; and providing shared content to the user receiving shared content according to the contentID of the shared node after the authentication succeeds; characterized in that the method further comprises: before receiving the shared content access request, organizing the nodes in a directory tree in the following way: allocating a contentID unique in the network storage system for each node in the system, wherein the contentID remains the same all the time; and associating the contentID with organization information of the node, wherein the organization information comprises a parentContentID of the node and a contentName of the node, wherein the associating is performed by assigning the organization information of the node to the contentID of the node, wherein the parentContentID is a contentID of a parent directory of a file in case the contentID identifies the file and the parentContentID is a contentID of a parent directory of a directory in case the contentID identifies the directory, wherein the contentName is a name of a content, wherein, when the node is a file, the organization information further comprises an ID of a physical entity corresponding to the node, wherein the ID of the physical entity corresponds to a lower layer storage path of the physical entity. allocating a contentID unique in the network storage system for each node in the system, wherein the contentID remains the same all the time; and associating the contentID with organization information of the node, wherein the organization information comprises a parentContentID of the node and a contentName of the node, wherein the associating is performed by assigning the organization information of the node to the contentID of the node, wherein the parentContentID is a contentID of a parent directory of a file in case the contentID identifies the file and the parentContentID is a contentID of a parent directory of a directory in case the contentID identifies the directory, wherein the contentName is a name of a content, wherein, when the node is a file, the organization information further comprises an ID of a physical entity corresponding to the node, wherein the ID of the physical entity corresponds to a lower layer storage path of the physical entity.