Embodiments of the present invention provide a sleep control method, apparatus and system for a virtual desktop. The sleep control method for a virtual desktop in the present invention comprises: a server receives a sleep request message sent by a client; the server determines, according to the sleep request message, whether an operation-free application runs on a virtual machine connected to the client, the operation-free application referring to an application not requiring an input operation of an input device of the client; if it is determined that the operation-free application does not run on the virtual machine of the client, the server sends a sleep allowance instruction to the client to instruct the client to enter a sleep state; and if it is determined that the operation-free application runs on the virtual machine of the client, the server sends a sleep prohibition instruction to the client to instruct the client not to enter the sleep state.