A downlink bandwidth part adjustment method, wherein the method is applicable to user equipment and the method comprises: determining (S1) whether at least one timer associated with multiple active downlink bandwidth parts of a current serving cell of the user equipment times out; and in response to that there is at least one timed-out timer among the at least one timer, deactivating (S2) each active downlink bandwidth part associated with the timed-out timer, and activating a downlink bandwidth part in a preset state corresponding to the each active downlink bandwidth part, wherein the preset state comprises a default state and/or an initial state, the method characterized in that the deactivating each active downlink bandwidth part associated with the timed-out timer, and activating a downlink bandwidth part in the preset state corresponding to the each active downlink bandwidth part comprises: in response to that the each active downlink bandwidth part associated with the timed-out timer is configured with the downlink bandwidth part in the default state, deactivating the each active downlink bandwidth part associated with the timed-out timer, and activating the downlink bandwidth part in the default state corresponding to the each active downlink bandwidth part associated with the timed-out timer; and in response to that the each active downlink bandwidth part associated with the timed-out timer is not configured with the downlink bandwidth part in the default state, deactivating the each active downlink bandwidth part associated with the timed-out timer, and activating the downlink bandwidth part in the initial state corresponding to the each active downlink bandwidth part associated with the timed-out timer. determining (S1) whether at least one timer associated with multiple active downlink bandwidth parts of a current serving cell of the user equipment times out; and in response to that there is at least one timed-out timer among the at least one timer, deactivating (S2) each active downlink bandwidth part associated with the timed-out timer, and activating a downlink bandwidth part in a preset state corresponding to the each active downlink bandwidth part, wherein the preset state comprises a default state and/or an initial state, the method characterized in that the deactivating each active downlink bandwidth part associated with the timed-out timer, and activating a downlink bandwidth part in the preset state corresponding to the each active downlink bandwidth part comprises: in response to that the each active downlink bandwidth part associated with the timed-out timer is configured with the downlink bandwidth part in the default state, deactivating the each active downlink bandwidth part associated with the timed-out timer, and activating the downlink bandwidth part in the default state corresponding to the each active downlink bandwidth part associated with the timed-out timer; and in response to that the each active downlink bandwidth part associated with the timed-out timer is not configured with the downlink bandwidth part in the default state, deactivating the each active downlink bandwidth part associated with the timed-out timer, and activating the downlink bandwidth part in the initial state corresponding to the each active downlink bandwidth part associated with the timed-out timer. <EOS>