A method for adjusting media stream transmission bandwidth and a related apparatus are provided. A media stream sending end acquires scores that are given, according to identifiers of multiple media streams, by a media stream receiving end to the media streams, where the multiple media streams are transmitted at a same transmission port, and these identifiers are described based on media stream content; when it is detected that congestion occurs or congestion is resolved, the media stream sending end performs transmission bandwidth adjustment on a corresponding media stream according to these scores, and therefore media stream transmission bandwidth adjustment may be performed, based on the media stream content, on the multiple media streams transmitted at the same transmission port.