Transmission processing methods and apparatuses of a data packet are provided. A User equipment (UE) carries out the following processing for media plane data to be sent: calling a Real-time Transport Protocol (RTP) stack to encapsulate the media plane data to obtain an initial RTP packet, and prohibiting calling an Internet Protocol (IP)/User Data Protocol (UDP) stack for encapsulating the initial RTP packet; and sending the processed media plane data to a base station.