Embodiments of the present invention disclose a video data transmission method and a related device. The method may include: when a base station receives information about a selection result and measurement configuration information, where the information about the selection result and the measurement configuration information are sent by a selection apparatus, determining, by the base station according to the selection result, that the present base station is a primary base station; acquiring, by the base station, channel quality information by using the measurement configuration information; and generating, by the base station, decision information according to the channel quality information and video service information that is acquired from a transmission conversion apparatus, and sending the decision information to the transmission conversion apparatus, which instructs a unicast service network element to perform unicast transmission for video data and/or instructs a multicast service network element to perform multicast transmission for video data.