The invention provides an uplink signal processing system, which comprises terminal equipment, relay equipment, head end equipment and optical network unit equipment, and is characterized in that the terminal equipment is used for receiving digital signals sent by a first user terminal, converting the digital signals into carrier signals and sending the carrier signals; the relay equipment is connected with the terminal equipment through a cable and used for receiving the carrier signals, performing gaining on the carrier signals and sending the gained carrier signals; the head end equipment is connected with the relay equipment through a cable and used for receiving the gained carrier signals, converting the gained carrier signals into digital signals and sending the digital signals; and the optical network unit equipment is connected with the head end equipment through a network cable and used for receiving the digital signals, converting the digital signal into optical signal and sending the optical signal to an optical line terminal.