Embodiments of this application provide a data stream transmission method. The method includes a sending device that dynamically determines a packet-loss-concealment policy based on first path status information of a path used to send a data stream. The sending device generates a packet-loss-concealment packet for the data stream according to the packet-loss-concealment policy. The sending device sends the data stream on the path. The data stream includes an original packet and the packet-loss-concealment packet. Therefore, when receiving the data stream, a receiving device decodes the data stream according to the packet-loss-concealment policy received from the sending device, and recovers, by using the packet-loss-concealment packet, an original packet lost in a transmission process. This effectively improves a packet loss recovery effect, and improves user experience.