This application discloses a congestion control method and apparatus. In this application, a network device obtains time information of one or more congestion packets in a sent first data stream, where the one or more congestion packet carries a flag indicating a congestion notification; when the first data stream is congested, obtains a first congestion notification packet based on the time information of the one or more congestion packets in the first data stream, where the first congestion notification packet notifies that a packet is congested beyond a first specified interval; and sends the first congestion notification packet. According to the solutions in this application, a rate of a data stream can be prevented from being increased when the data stream is congested, and packet transmission efficiency is improved.