This application provides a flow rate control method and apparatus. The flow rate control method in this application includes: receiving N explicit congestion notification packets CNPs from a first device, where the N CNPs correspond to a first data flow, and N is a natural number; and sending M CNPs to a second device based on the N CNPs, where the M CNPs correspond to the first data flow, and M is an integer greater than N. This application resolves a problem that rate increase processing is still performed on a data flow when the data flow is congested.