A multi-mode convergence method, a multi-mode combination method, and devices thereof are provided. The multi-mode convergence method includes the following steps. Data from multi-mode base band units (BBUs) is received and separated into downlink service data and operation maintenance data. A channel configuration is generated according to the operation maintenance data. The downlink service data of a corresponding mode is selected according to the channel configuration, and the downlink service data and the operation maintenance data are consolidated, and the consolidated data is sent to corresponding remote radio unit (RRUs). The multi-mode convergence method, the multi-mode combination method, and devices thereof are adopted, so as to accomplish functions, such as multi-mode and pseudo noise (PN) multiplexing, to decrease complexity of a multi-mode system, and provide a function of multi-mode coexistent optical fiber.