A method for monitoring a physical channel, applicable for a terminal device, comprising: performing (S 102), by the terminal device, physical downlink control channel, PDCCH, monitoring on a first serving cell according to a first serving cell group, wherein the terminal device is configured with at least one serving cell group, wherein the first serving cell is a serving cell comprised in the first serving cell group, and the first serving cell group is a serving cell group in the at least one serving cell group, wherein performing, by the terminal device, PDCCH monitoring on the first serving cell according to the first serving cell group comprises: performing, by the terminal device, PDCCH monitoring on the first serving cell according to a search space, SS, set corresponding to a first group identifier; in response to detecting a first DCI format on a second serving cell in the first serving cell group by the terminal device according to the SS set corresponding to the first group identifier, performing, by the terminal device, starting from a first-slot on the first serving cell, PDCCH monitoring on the first serving cell according to a SS set corresponding to a second group identifier, and stopping performing PDCCH monitoring according to the SS set corresponding to the first group identifier; in response to detecting a second DCI format by the terminal device in at least one SS set on a third serving cell in the first serving cell group, setting, by the terminal device, a first timer to a first timing value; characterized in that the first-slot comprises a first slot after at least P1 symbols after a last symbol of the PDCCH carrying the first DCI format; a slot corresponding to the first timer is determined according to a second subcarrier spacing, and the second subcarrier spacing is a minimum subcarrier spacing among subcarrier spacings corresponding to serving cells comprised in the first serving cell group. performing (S 102), by the terminal device, physical downlink control channel, PDCCH, monitoring on a first serving cell according to a first serving cell group, wherein the terminal device is configured with at least one serving cell group, wherein the first serving cell is a serving cell comprised in the first serving cell group, and the first serving cell group is a serving cell group in the at least one serving cell group, wherein performing, by the terminal device, PDCCH monitoring on the first serving cell according to the first serving cell group comprises: performing, by the terminal device, PDCCH monitoring on the first serving cell according to a search space, SS, set corresponding to a first group identifier; in response to detecting a first DCI format on a second serving cell in the first serving cell group by the terminal device according to the SS set corresponding to the first group identifier, performing, by the terminal device, starting from a first-slot on the first serving cell, PDCCH monitoring on the first serving cell according to a SS set corresponding to a second group identifier, and stopping performing PDCCH monitoring according to the SS set corresponding to the first group identifier; in response to detecting a second DCI format by the terminal device in at least one SS set on a third serving cell in the first serving cell group, setting, by the terminal device, a first timer to a first timing value; characterized in that the first-slot comprises a first slot after at least P1 symbols after a last symbol of the PDCCH carrying the first DCI format; a slot corresponding to the first timer is determined according to a second subcarrier spacing, and the second subcarrier spacing is a minimum subcarrier spacing among subcarrier spacings corresponding to serving cells comprised in the first serving cell group. performing, by the terminal device, PDCCH monitoring on the first serving cell according to a search space, SS, set corresponding to a first group identifier; in response to detecting a first DCI format on a second serving cell in the first serving cell group by the terminal device according to the SS set corresponding to the first group identifier, performing, by the terminal device, starting from a first-slot on the first serving cell, PDCCH monitoring on the first serving cell according to a SS set corresponding to a second group identifier, and stopping performing PDCCH monitoring according to the SS set corresponding to the first group identifier; in response to detecting a second DCI format by the terminal device in at least one SS set on a third serving cell in the first serving cell group, setting, by the terminal device, a first timer to a first timing value; characterized in that the first-slot comprises a first slot after at least P1 symbols after a last symbol of the PDCCH carrying the first DCI format; a slot corresponding to the first timer is determined according to a second subcarrier spacing, and the second subcarrier spacing is a minimum subcarrier spacing among subcarrier spacings corresponding to serving cells comprised in the first serving cell group.