A method for data transmission, applied to a terminal device, the method comprising: detecting downlink control information, DCI, carried by a physical downlink control channel, PDCCH, in at least one control resource set, CORESET; determining transmission configuration indicator, TCI, state indication information in the detected DCI, wherein the detected DCI is used for scheduling a data channel; acquiring data channel configuration information corresponding to the at least one CORESET through acquiring a correspondence between identification information of the at least one CORESET and identification information of a data channel configuration information through higher layer signaling from a network side using a data channel configuration index that is an index of one data channel configuration information among multiple data channel configuration information configured on the network side, determining a transmission parameter of the data channel based on the data channel configuration information corresponding to the at least one CORESET where the DCI is detected, wherein the transmission parameter comprises candidate TCI states of the data channel, and wherein, if the network side has not configured data channel configuration information corresponding to the at least one CORESET for the terminal device through the higher layer signaling, default data channel configuration information is used to determine the transmission parameter; and receiving the data channel based on the transmission parameter; wherein receiving the data channel based on the transmission parameter comprises: determining quasi co-location, QCL, assumption for detection of the data channel based on the candidate TCI states of the data channel and the TCI state indication information, and receiving the data channel based on the QCL assumption. detecting downlink control information, DCI, carried by a physical downlink control channel, PDCCH, in at least one control resource set, CORESET; determining transmission configuration indicator, TCI, state indication information in the detected DCI, wherein the detected DCI is used for scheduling a data channel; acquiring data channel configuration information corresponding to the at least one CORESET through acquiring a correspondence between identification information of the at least one CORESET and identification information of a data channel configuration information through higher layer signaling from a network side using a data channel configuration index that is an index of one data channel configuration information among multiple data channel configuration information configured on the network side, determining a transmission parameter of the data channel based on the data channel configuration information corresponding to the at least one CORESET where the DCI is detected, wherein the transmission parameter comprises candidate TCI states of the data channel, and wherein, if the network side has not configured data channel configuration information corresponding to the at least one CORESET for the terminal device through the higher layer signaling, default data channel configuration information is used to determine the transmission parameter; and receiving the data channel based on the transmission parameter; wherein receiving the data channel based on the transmission parameter comprises: determining quasi co-location, QCL, assumption for detection of the data channel based on the candidate TCI states of the data channel and the TCI state indication information, and receiving the data channel based on the QCL assumption. determining quasi co-location, QCL, assumption for detection of the data channel based on the candidate TCI states of the data channel and the TCI state indication information, and receiving the data channel based on the QCL assumption. <EOS>