The embodiments of the present invention disclose a method, a device, and a system for controlling multichannel cascade between two media control servers. The method comprises: receiving a service request message; choosing a target channel among all the channels multichannel-cascaded with an opposite cascaded media control server according to the service request message and a preset channel usage rule; and sending information about the determined target channel to the opposite cascaded media control server so as to enable the opposite cascaded media control server to carry out code stream switching according to the information about the target channel. The method disclosed in the embodiments of the present invention saves cascaded channels and improves the utilization of cascaded channels, thereby saving channel resources.