Method and device for compressing data packet

Disclosed is a method for compressing a data packet in a communication system. The method comprises: performing, by a first apparatus, according to a compression algorithm, a compression processing on data in a data packet; and encapsulating, by the first apparatus, the compressed data into a data packet, header information of the data packet comprising: compression state indication information and extension header indication information, data in the data packet comprising: data different between transmitted data and data prior to the compression processing and awaiting transmission, and feature information corresponding to data identical between the transmitted data and the data prior to the compression processing and awaiting transmission; wherein the compression state indication information indicates whether the data packet is compressed, and the extension header indication information indicates whether an extension header appears in an option field of the data packet. Also disclosed is a device for compressing the data packet in the communication system.