The present invention provides a method and corresponding device of processing and parsing a to-be-transmitted data packet in a communication network, such as a LTE system. A sub-header that is used for a header portion of a transmitted data packet is generated for each component data packet constituting the transmitted data packet, containing: original data packet ID for indicating an original data packet which the component data packet belongs to; segmentation processing ID for indicating times of segmentation happened to the original data packet in order to the component data packet, and a data segment which said component data packet belongs to after each segmentation; data amount IF for indicating a data amount of a data portion of the data packet. With the technical solution provided by the present invention, the header structure definition of a data packet is optimized, and the transmission resource utilization efficiency is improved.