A congestion control processing method uses a two-level scheduling manner of a forwarding device and a destination device, where the network device of a data center network performs coarse-grained bandwidth allocation based on weights of flows destined for different destination devices. The network device allocates each flow a bandwidth that does not cause congestion, and notifies the destination device. The destination device performs fine-grained division, determines a maximum sending rate for each flow, and notifies a packet sending device of the maximum sending rate.