A method for activating or updating a pathloss reference signal corresponding to a sounding reference signal, the method comprising: receiving, by a terminal device, a Medium Access Control Control Element sent by a network device, wherein the MAC CE comprises at least one Sounding Reference Signal resource set field and/or at least one pathloss Reference Signal field, the at least one SRS resource set field is used to indicate at least one SRS resource set, and the at least one pathloss RS field is used to indicate at least one pathloss RS corresponding to the at least one SRS resource set; and updating or activating, by the terminal device, the at least one pathloss RS corresponding to the at least one SRS resource set according to the MAC CE; wherein the MAC CE comprises the at least one SRS resource set field and the at least one pathloss RS field; wherein: the at least one SRS resource set field has a one-to-one correspondence with the at least one pathloss RS field, one SRS resource set field in the at least one SRS resource set field is used to indicate an identity of one SRS resource set in the at least one SRS resource set, and one pathloss RS field in the at least one pathloss RS field is used to indicate an identity of one pathloss RS in the at least one pathloss RS; the method characterised in that it further comprises: determining, by the terminal device, a size of each SRS resource set field in the at least one SRS resource set field according to a maximum number of the at least one SRS resource set; wherein if the maximum number of the at least one SRS resource set is 16, each SRS resource set field occupies 4 bits. receiving, by a terminal device, a Medium Access Control Control Element sent by a network device, wherein the MAC CE comprises at least one Sounding Reference Signal resource set field and/or at least one pathloss Reference Signal field, the at least one SRS resource set field is used to indicate at least one SRS resource set, and the at least one pathloss RS field is used to indicate at least one pathloss RS corresponding to the at least one SRS resource set; and updating or activating, by the terminal device, the at least one pathloss RS corresponding to the at least one SRS resource set according to the MAC CE; wherein the MAC CE comprises the at least one SRS resource set field and the at least one pathloss RS field; wherein: the at least one SRS resource set field has a one-to-one correspondence with the at least one pathloss RS field, one SRS resource set field in the at least one SRS resource set field is used to indicate an identity of one SRS resource set in the at least one SRS resource set, and one pathloss RS field in the at least one pathloss RS field is used to indicate an identity of one pathloss RS in the at least one pathloss RS; the method characterised in that it further comprises: determining, by the terminal device, a size of each SRS resource set field in the at least one SRS resource set field according to a maximum number of the at least one SRS resource set; wherein if the maximum number of the at least one SRS resource set is 16, each SRS resource set field occupies 4 bits. the at least one SRS resource set field has a one-to-one correspondence with the at least one pathloss RS field, one SRS resource set field in the at least one SRS resource set field is used to indicate an identity of one SRS resource set in the at least one SRS resource set, and one pathloss RS field in the at least one pathloss RS field is used to indicate an identity of one pathloss RS in the at least one pathloss RS; the method characterised in that it further comprises: determining, by the terminal device, a size of each SRS resource set field in the at least one SRS resource set field according to a maximum number of the at least one SRS resource set; wherein if the maximum number of the at least one SRS resource set is 16, each SRS resource set field occupies 4 bits. determining, by the terminal device, a size of each SRS resource set field in the at least one SRS resource set field according to a maximum number of the at least one SRS resource set; wherein if the maximum number of the at least one SRS resource set is 16, each SRS resource set field occupies 4 bits.