The embodiment of the invention discloses a method and a device for the virtual memory. The method comprises the following steps: acquiring a volume managing manner of a logic unit LUN of a memory array, and recording the volume managing manner in splicing data; constructing a virtual LUN according to the LUN and the splicing data, and mapping the virtual LUN onto to the host for being read, written and accessed; modifying the destination address of the I/O data packet according to the splicing data after the receipt of an input I/ output O data packet delivered by the host, delivering the I/O data packet to the virtual LUN, and delivering the I/O data packet delivered to the virtual LUN to the memory array according to the splicing data. In addition, the position for the delivery of I/O data packet to the memory array is the same as the destination address of the I/O data packet, which is not modified. The embodiment of the invention realizes the memory integration, and shields the difference caused by different hosts and volume managing manners coming from different system platforms.