A dynamic time adjustment method, wherein the method is executed by a network-side device, the network-side device comprises at least two transceivers, and the dynamic time adjustment method comprises: obtaining, by the network-side device, a length Mds_New of a new downstream transmission duration; characterized in that the dynamic time adjustment method further comprises: adjusting, by the network-side device, a length of a downstream transmission duration of the at least two transceivers from a length Mds_Old of a currently used downstream transmission duration to Mds_New, and adjusting a length of an upstream transmission duration of the at least two transceivers from a length Mus_Old of a currently used upstream transmission duration to a length Mus_New of a new upstream transmission duration, wherein a first transceiver is any one of the at least two transceivers of the network-side device, a sum of Mds_New and Mus_New is equal to a length of one transmission frame minus a length of an upstream and downstream switching duration, and the upstream and downstream switching duration is a duration spent by the first transceiver to switch from a receiving state to a sending state and switch from the sending state to the receiving state; and when Mds_New is greater than Mds_Old, keeping, by the network-side device, silent or sending, along twisted pair cables, an idle symbol in a transition zone of the new downstream transmission duration of the at least two transceivers, wherein the transition zone of the new downstream transmission duration of the at least two transceivers is an additional zone of the new downstream transmission duration compared with the currently used downstream transmission duration. obtaining, by the network-side device, a length Mds_New of a new downstream transmission duration; characterized in that the dynamic time adjustment method further comprises: adjusting, by the network-side device, a length of a downstream transmission duration of the at least two transceivers from a length Mds_Old of a currently used downstream transmission duration to Mds_New, and adjusting a length of an upstream transmission duration of the at least two transceivers from a length Mus_Old of a currently used upstream transmission duration to a length Mus_New of a new upstream transmission duration, wherein a first transceiver is any one of the at least two transceivers of the network-side device, a sum of Mds_New and Mus_New is equal to a length of one transmission frame minus a length of an upstream and downstream switching duration, and the upstream and downstream switching duration is a duration spent by the first transceiver to switch from a receiving state to a sending state and switch from the sending state to the receiving state; and when Mds_New is greater than Mds_Old, keeping, by the network-side device, silent or sending, along twisted pair cables, an idle symbol in a transition zone of the new downstream transmission duration of the at least two transceivers, wherein the transition zone of the new downstream transmission duration of the at least two transceivers is an additional zone of the new downstream transmission duration compared with the currently used downstream transmission duration. adjusting, by the network-side device, a length of a downstream transmission duration of the at least two transceivers from a length Mds_Old of a currently used downstream transmission duration to Mds_New, and adjusting a length of an upstream transmission duration of the at least two transceivers from a length Mus_Old of a currently used upstream transmission duration to a length Mus_New of a new upstream transmission duration, wherein a first transceiver is any one of the at least two transceivers of the network-side device, a sum of Mds_New and Mus_New is equal to a length of one transmission frame minus a length of an upstream and downstream switching duration, and the upstream and downstream switching duration is a duration spent by the first transceiver to switch from a receiving state to a sending state and switch from the sending state to the receiving state; and when Mds_New is greater than Mds_Old, keeping, by the network-side device, silent or sending, along twisted pair cables, an idle symbol in a transition zone of the new downstream transmission duration of the at least two transceivers, wherein the transition zone of the new downstream transmission duration of the at least two transceivers is an additional zone of the new downstream transmission duration compared with the currently used downstream transmission duration.