The application provides a method and a router for sending and processing data. In the method, a first router receives a first Internet Protocol IP data packet sent by a network server, where the first IP data packet carries a first data adding instruction; and the first router searches, according to the first data adding instruction, a first local cache for to-be-added data that is indicated by the first data adding instruction, adds, to the first IP data packet, the to-be-added data that is indicated by the first data adding instruction, to form a second IP data packet, and sends the second IP data packet. Because a router can add data to an IP data packet according to a data adding instruction, flexibility of data combinations is improved, and because the IP data packet can support multiple times of data adding, the flexibility of data combinations is further improved.