A bandwidth allocation method and a routing device are provided. The bandwidth allocation method includes: obtaining traffic of a member port belonging to a binding link (101); and allocating corresponding bandwidth to the member port according to total bandwidth of a centralized scheduler and the traffic of the member port (102). By allocating the bandwidth to the member port belonging to the binding link through the centralized scheduler, the bandwidth may be flexibly allocated to the member port according to the traffic of the member port, so that not only the accuracy of allocating the bandwidth to the member port is ensured, but also bandwidth resources on the binding link are saved.