Provided are a feedback information processing method, device and system, a base station and a terminal. The method includes: multiplexing, by a first node, feedback information for a plurality of second nodes in a media access control protocol data unit (MAC PDU), where the feedback information is information generated after the first node correctly receives transmission blocks from the second nodes, and the feedback includes a plurality of pieces of bit information. After the first node multiplexes the feedback information for the plurality of second nodes in the MAC PDU, a radio network temporary identifier (RNTI) is used in a process that the first node delivers the feedback information to the plurality of second nodes.