The embodiments of the present invention relate to the field of communications technologies, and disclose a lossless adjustment method of ODUflex channel bandwidth. The lossless adjustment method includes: adjusting, according to a bandwidth adjustment indication request information, the number of time slots occupied by an ODUflex frame in a higher order optical channel data unit of each network node on an ODUflex channel; and adjusting, according to a rate adjustment indication information, a transmission rate of the ODUflex frame of each network node on the ODUflex channel; the bandwidth adjustment indication request informatioin and the rate adjustment indication information are encapsulated into the HO ODU overhead. The embodiments of the present invention achieve a lossless adjustment of ODUflex channel bandwidth.