Optical network system and transmission method oriented to sampling value service in transformer substation

The invention relates to an optical network system and transmission method oriented to a sampling value service in a transformer substation. The optical network system comprises m*n*k electronic current/voltage transformers, m*n combination units, m*n protection devices, m*n measurement and controlling devices, m slave nodes, one main node, a network analysis device, a bus difference protection device and a fault recording and playing device. The sampling data of the combination unit at each interval in the transformer substation is transmitted to the protection device and the measurement and controlling device at the abovementioned interval, the network analysis device, the bus difference protection device and the fault recording and playing device through the slave nodes and the main nodes. The system is suitable for different transmission protocols and rate levels; the problem of data blockage during exchange of the sampling data in the slave nodes is solved; and the network performance is improved.