A method, device and system for implementing bidirectional traffic on the same path in an aggregation group are provided, wherein the method includes that a portal of an LAG receives indication information sent by an opposite end of the LAG, wherein the indication information carries port indexes of the opposite end and/or a traffic distribution method of the opposite end; the portal determines port indexes of the portal and/or traffic distribution method of the portal according to the indication information; the portal distributes traffic according to the determined port indexes and/or traffic distribution method The disclosure solves a technical problem in the prior art that port protection cannot be implemented due to the inability to ensure that traffic of the same service can be transmitted on the same aggregation link, thus effectively ensuring that the same service selects the same aggregation link bi-directionally on two ends of an aggregation group and implementing the technical effect of protection on an interconnect port.