This invention discloses an MAC layer sending processing method, including: process the sending data with QoS-based multiplexing, cascading segmentation, ARQ, generating transmission block, HARQ, and other processes. The invention also discloses an MAC layer receiving processing method, including: process the receiving data with HARQ, transmission block queue distribution, decomposition, retransmission, demultiplexing, and other processes. The invention also discloses the base station and UE using the above MAC layer processing method. According to the invention, through the transmission channel types, it can use less MAC layer entities to handle transmission channel, thereby reducing the complexity of MAC layer processing, and improving the MAC layer efficiency on the business processes, thereby enhancing the system efficiency. In addition, since the MAC layer processing entities of the invention are few, making data processing steps reduced through the MAC layer, thereby reducing the data processing delay.