Disclosed are an uplink precoding method, device and system. A terminal device transmits an SRS on at least one SRS resource, and receives DCI used by a network side to schedule uplink data transmission, the DCI comprising RI and/or SRI, then determines a precoding approach for the uplink data according to the RI and/or SRI and at least one SRS resource, precodes the uplink data according to the precoding approach, and transmits the precoded uplink data. By applying the solution of the present invention, signaling overhead can be reduced.