A remote desktop system includes a primary virtual machine, a plurality of secondary virtual machines, a primary terminal configured to log in to the primary virtual machine, and a secondary terminal configured to log in to a secondary virtual machine. When a user of the primary virtual machine needs to share image data of the primary virtual machine with a user of the secondary terminal for viewing, the primary virtual machine sends the image data to the primary terminal, and then the primary terminal shares the image data with the secondary terminal. This reduces data transmission pressure on a communications network between a virtual machine center and a terminal center.