A communication method, comprising: determining a first subcarrier spacing from M subcarrier spacings, wherein the M subcarrier spacings are subcarrier spacings corresponding to L uplink carriers used by a terminal device, and L ≥ M ≥ 2; and determining an effective moment of a timing advance, TA, of each of the L uplink carriers based on the first subcarrier spacing; wherein the determining an effective moment of a timing advance, TA, of each of the L uplink carriers based on the first subcarrier spacing comprises: determining a first time interval based on the first subcarrier spacing, wherein the first time interval is a time interval between a receiving moment of a downlink signal and the effective moment of the TA; and determining the effective moment of the TA of each of the L uplink carriers based on the first time interval; and wherein the determining a first time interval based on the first subcarrier spacing comprises: determining the first time interval based on third duration, wherein the third duration is maximum duration that is allowed to be indicated by a 12-bit or 6-bit timing advance command, TAC, when the third duration is determined based on the first subcarrier spacing, wherein: the determining a first subcarrier spacing from M subcarrier spacings comprises: determining the first subcarrier spacing, wherein the first subcarrier spacing is a smaller subcarrier spacing between a third subcarrier spacing and a fourth subcarrier spacing, the third subcarrier spacing being a minimum subcarrier spacing among the M subcarrier spacings corresponding to the L uplink carriers and the fourth subcarrier spacing being a subcarrier spacing at which the terminal transmits a message 3 in a random access process. determining a first subcarrier spacing from M subcarrier spacings, wherein the M subcarrier spacings are subcarrier spacings corresponding to L uplink carriers used by a terminal device, and L ≥ M ≥ 2; and determining an effective moment of a timing advance, TA, of each of the L uplink carriers based on the first subcarrier spacing; wherein the determining an effective moment of a timing advance, TA, of each of the L uplink carriers based on the first subcarrier spacing comprises: determining a first time interval based on the first subcarrier spacing, wherein the first time interval is a time interval between a receiving moment of a downlink signal and the effective moment of the TA; and determining the effective moment of the TA of each of the L uplink carriers based on the first time interval; and determining a first time interval based on the first subcarrier spacing, wherein the first time interval is a time interval between a receiving moment of a downlink signal and the effective moment of the TA; and determining the effective moment of the TA of each of the L uplink carriers based on the first time interval; and wherein the determining a first time interval based on the first subcarrier spacing comprises: determining the first time interval based on third duration, wherein the third duration is maximum duration that is allowed to be indicated by a 12-bit or 6-bit timing advance command, TAC, when the third duration is determined based on the first subcarrier spacing, wherein: the determining a first subcarrier spacing from M subcarrier spacings comprises: determining the first subcarrier spacing, wherein the first subcarrier spacing is a smaller subcarrier spacing between a third subcarrier spacing and a fourth subcarrier spacing, the third subcarrier spacing being a minimum subcarrier spacing among the M subcarrier spacings corresponding to the L uplink carriers and the fourth subcarrier spacing being a subcarrier spacing at which the terminal transmits a message 3 in a random access process. determining the first time interval based on third duration, wherein the third duration is maximum duration that is allowed to be indicated by a 12-bit or 6-bit timing advance command, TAC, when the third duration is determined based on the first subcarrier spacing, wherein: the determining a first subcarrier spacing from M subcarrier spacings comprises: determining the first subcarrier spacing, wherein the first subcarrier spacing is a smaller subcarrier spacing between a third subcarrier spacing and a fourth subcarrier spacing, the third subcarrier spacing being a minimum subcarrier spacing among the M subcarrier spacings corresponding to the L uplink carriers and the fourth subcarrier spacing being a subcarrier spacing at which the terminal transmits a message 3 in a random access process.