The embodiments of the present invention relate to the field of communications technologies, and disclose a lossless adjustment method of ODUflex channel bandwidth and an ODUflex channel. The lossless adjustment method includes: respectively adjusting, according to bandwidth adjustment indication request information, a time slot occupied by an ODUflex frame in a higher order optical channel data unit at an egress side of each network node on an ODUflex channel; and adjusting, according to rate adjustment indication information, a transmission rate of the ODUflex frame of each network node on the ODUflex channel, to enable the transmission rate of each network node on the ODUflex channel to be unified.