A flexible Ethernet group establishment method using the Network Time Protocol, NTP, comprising: a) determining, by a far-end device (200; 300), that there are at least M physical layer, PHY, links, wherein M is an integer greater than or equal to 2; b) receiving, by the far-end device (200; 300) over the at least M PHY links, at least M delay test requests sent by a near-end device, wherein one delay test request sent by the near-end device is received over each of the at least M PHY links, and an i th delay test request is received over a PHY link i of the at least M PHY links; c) determining, by the far-end device (200, 300), at least M receiving time points at which the at least M delay test requests are received, wherein a time point at which the i th delay test request is received is a receiving time point T 1i; and d) determining, by the far-end device (200, 300), M PHY links used to establish a flexible Ethernet group, from the at least M PHY links based on the at least M receiving time points, wherein a delay difference between any two of the M PHY links: a PHY link a and a PHY link b, satisfies a preset delay condition; and e1) wherein at least two of the at least M delay test requests are sent by the near-end device at different sending time points, wherein the i th delay test request comprises first information, the first information is used to indicate a sending time point T 2i at which the near-end device sends the i th delay test request over the PHY link i, and the delay difference Δ D ab between the PHY link a and the PHY link b is determined based on formula Δ D ab = ( T 1b - T 2b)-( T 1a - T 2a); or e2) wherein the at least M delay test requests are sent by the near-end device at a same sending time point wherein the delay difference Δ D ab between the PHY link a and the PHY link b is determined based on formula Δ D ab = T 1b - T 1a. a) determining, by a far-end device (200; 300), that there are at least M physical layer, PHY, links, wherein M is an integer greater than or equal to 2; b) receiving, by the far-end device (200; 300) over the at least M PHY links, at least M delay test requests sent by a near-end device, wherein one delay test request sent by the near-end device is received over each of the at least M PHY links, and an i th delay test request is received over a PHY link i of the at least M PHY links; c) determining, by the far-end device (200, 300), at least M receiving time points at which the at least M delay test requests are received, wherein a time point at which the i th delay test request is received is a receiving time point T 1i; and d) determining, by the far-end device (200, 300), M PHY links used to establish a flexible Ethernet group, from the at least M PHY links based on the at least M receiving time points, wherein a delay difference between any two of the M PHY links: a PHY link a and a PHY link b, satisfies a preset delay condition; and e1) wherein at least two of the at least M delay test requests are sent by the near-end device at different sending time points, wherein the i th delay test request comprises first information, the first information is used to indicate a sending time point T 2i at which the near-end device sends the i th delay test request over the PHY link i, and the delay difference Δ D ab between the PHY link a and the PHY link b is determined based on formula Δ D ab = ( T 1b - T 2b)-( T 1a - T 2a); or e2) wherein the at least M delay test requests are sent by the near-end device at a same sending time point wherein the delay difference Δ D ab between the PHY link a and the PHY link b is determined based on formula Δ D ab = T 1b - T 1a.