A memory access device allocate a memory resource to a node in a system to reduce maintenance overheads of the system and implement flexible scheduling of memory resources. The device includes a cloud control device on the side of a requesting node and a cloud control device on the side of a contributing node. The cloud control device on the side of the requesting node generates a request packet for accessing to-be-accessed data stored in the contributing node which provides memory resource, sends the request packet to the contributing node t. The cloud control device on the side of the contributing node receives the request packet, provides a request message to the contributing node, generates the response packet for the contributing node, and sends the response packet to the requesting node.