Abstract: The disclosure claims a bandwidth adjustment method and system for Optical channel Data Unit flexible (ODUflex) based on a Generic Framing Procedure (GFP), wherein, the method includes that: (501) a source end sends a bandwidth adjustment control frame which contains bandwidth adjustment parameters; (503) a plurality of intermediate nodes forward the bandwidth adjustment control frame to a sink end via an ODUflex link, during the forwarding process, the plurality of intermediate nodes determine that resource thereof can satisfy the bandwidth adjustment parameters, and then reserve the bandwidth adjustment resource; (505) after receiving the bandwidth adjustment control frame, the sink end feeds back an adjustment acknowledgment frame which contains adjustment acknowledgment information to the source end via the plurality of intermediate nodes; (507) the plurality of intermediate nodes use the reserved bandwidth adjustment resource to implement adjustment for the bandwidth of the ODUflex link according to the