The present invention provides a method and an apparatus for transmitting a physical layer operations administration and maintenance message, wherein the method comprises: splicing multiple messages with a sum of the length of message contents less than a predetermined length into a message group by a predetermined manner, and transmitting the message group in a gigabit passive optical network transmission convergence frame. By the invention, the problems of wasting the bandwidth, prolonging the time of message interaction and reducing the reliability of the message interaction in the prior art are solved, thereby effectively reducing the occupation of the bandwidth and the time of the message interaction, and improving the reliability of the message interaction.