The embodiment of the invention provides an optical transmission system, a scheduling node, a wave combining node and a wave dividing node. In the embodiment of the invention, the optical transmissionsystem can comprise a wave combination node and a wave division node, the wave combination node comprises at least two first optical path selection devices and an optical path synthesis device, optical path signals received by the at least two first optical path selection devices are synthesized through the optical path synthesis device, and two paths of synthesized optical path signals are sent,so that the wave combination node can realize a combined optical path selection device, the transmission rate of the optical signal is flexibly adjusted, that is to say, grids for optical signal transmission are flexibly adjusted, so that the channel interval of the optical signal is adjusted, the optimal channel interval is provided according to different electric layer rates, and meanwhile, thewave combination node can also provide more signal input ports, so that the access capability of the wave combining and dividing function is improved, the optical transmission system, the schedulingnode, the wave combining node and the wave dividing node are suitable for the multi-rate hybrid networking application scene, and meanwhile, the function of light splitting protection is realized.