A signal transmission method, comprising: monitoring, by a terminal device based on a size of first downlink control information, DCI, the first DCI and a second DCI that are sent by a network device, wherein the first DCI is carried on a power saving signal shared by a plurality of terminal devices comprising the terminal device, and the second DCI is carried on a terminal device specific power saving signal; and determining, by the terminal device based on the detected first DCI and the detected second DCI, whether to monitor a data channel in a first time period; wherein the first DCI comprises at least one information block, each of the at least one information block comprises at least one information field, and different information blocks are used to indicate parameters used by different terminal devices to monitor a data channel in the first time period; the at least one information block comprises a first information block, and an information field in the first information block is used to indicate a parameter used by the terminal device to monitor a data channel in the first time period; characterised in that the information field in the first information block is used to indicate one of several status value combinations of several information fields included in the second DCI configured by higher layer signaling or predefined in a standard, and wherein the several information fields included in the second DCI comprise a bandwidth part identification, BWP ID, information field, a time domain scheduling indicator information field, a trigger reference signal, RS, resource indicator information field, and a carrier transmission indicator information field. monitoring, by a terminal device based on a size of first downlink control information, DCI, the first DCI and a second DCI that are sent by a network device, wherein the first DCI is carried on a power saving signal shared by a plurality of terminal devices comprising the terminal device, and the second DCI is carried on a terminal device specific power saving signal; and determining, by the terminal device based on the detected first DCI and the detected second DCI, whether to monitor a data channel in a first time period; wherein the first DCI comprises at least one information block, each of the at least one information block comprises at least one information field, and different information blocks are used to indicate parameters used by different terminal devices to monitor a data channel in the first time period; the at least one information block comprises a first information block, and an information field in the first information block is used to indicate a parameter used by the terminal device to monitor a data channel in the first time period; characterised in that the information field in the first information block is used to indicate one of several status value combinations of several information fields included in the second DCI configured by higher layer signaling or predefined in a standard, and wherein the several information fields included in the second DCI comprise a bandwidth part identification, BWP ID, information field, a time domain scheduling indicator information field, a trigger reference signal, RS, resource indicator information field, and a carrier transmission indicator information field.