The invention discloses a method and a system for automatic discovery of a centralized optical channel based on a hybrid network. The method comprises the following steps of obtaining all equipment data in the hybrid network; utilizing a centralized controller to create an optical channel discovery message and packaging the optical channel discovery message to a data frame to be sent to a first single domain controller at a sending end; inserting the optical channel discovery message obtained by parsing the data frame into a data field and sending the data field to a second single domain controller at a receiving end; packaging the optical channel discovery message parsed from the data field into a data frame and sending the data frame to the centralized controller; and parsing the received data frame and determining distribution of the optical channel in the hybrid network. According to the method and the system, the active discovery is carried out on the optical channel in the centralized control hybrid network, and the optical channel between the first single domain controller at the sending end and the second single domain controller at the receiving end is quickly discovered through the centralized controller, so that the requirements for centralized management and maintenance of topological data in the hybrid network are met.