A bandwidth part processing method, comprising: receiving, by a terminal (170, 180, 210, 220, 250), first information and second information that are sent (S201, S1401) by a network device (190, 200, 230, 240, 260) wherein the first information is used to indicate that at least one default bandwidth part BWP each corresponds to at least two active BWPs, the second information is used to indicate that the at least two active BWPs correspond to at least one first timer (t1, t2, t3), and the first timer is a timer used by the terminal to perform deactivation processing on at least one of the at least two active BWPs; and performing, by the terminal, deactivation processing on the at least one of the at least two active BWPs and activation processing on a BWP in the at least one default BWP based on the first information and the second information, or performing deactivation processing on the at least one of the at least two active BWPs based on the first information and the second information; receiving, by the terminal, third information sent by the network device, wherein the third information is used to indicate that all active BWPs correspond to one second timer, and the second timer is a timer used by the terminal to perform deactivation processing on all active BWPs corresponding to a first timer that does not expire; and the performing, by the terminal, deactivation processing on the at least one of the at least two active BWPs and activation processing on a BWP in the at least one default BWP based on the first information and the second information comprises: when the second timer expires and there is a first timer that does not expire, performing, by the terminal based on the first information, the second information, and the third information, deactivation processing on all active BWPs corresponding to the first timer that does not expire and activation processing on a default BWP corresponding to each of the active BWPs. receiving, by a terminal (170, 180, 210, 220, 250), first information and second information that are sent (S201, S1401) by a network device (190, 200, 230, 240, 260) wherein the first information is used to indicate that at least one default bandwidth part BWP each corresponds to at least two active BWPs, the second information is used to indicate that the at least two active BWPs correspond to at least one first timer (t1, t2, t3), and the first timer is a timer used by the terminal to perform deactivation processing on at least one of the at least two active BWPs; and performing, by the terminal, deactivation processing on the at least one of the at least two active BWPs and activation processing on a BWP in the at least one default BWP based on the first information and the second information, or performing deactivation processing on the at least one of the at least two active BWPs based on the first information and the second information; receiving, by the terminal, third information sent by the network device, wherein the third information is used to indicate that all active BWPs correspond to one second timer, and the second timer is a timer used by the terminal to perform deactivation processing on all active BWPs corresponding to a first timer that does not expire; and the performing, by the terminal, deactivation processing on the at least one of the at least two active BWPs and activation processing on a BWP in the at least one default BWP based on the first information and the second information comprises: when the second timer expires and there is a first timer that does not expire, performing, by the terminal based on the first information, the second information, and the third information, deactivation processing on all active BWPs corresponding to the first timer that does not expire and activation processing on a default BWP corresponding to each of the active BWPs.