The invention discloses an uplink transmission method, apparatus and device of an LAA system. The method comprises the following steps: a base station sets the same backoff time for the scheduled UE in the same group, and sets different backoff times for the scheduled UE in different groups, wherein the scheduled UE in the same group contains all UE served by the same LAA unauthorized cell at the same scheduling moment, or all UE served by the same LAA unauthorized cell on the same sub-frame. The invention further discloses an apparatus and device for realizing the method.