A method for transmitting data, comprising: receiving, by a terminal device, downlink control information, DCI, wherein the DCI is used for scheduling physical downlink shared channel, PDSCH, transmission in multiple time domain resource units, and the DCI is further used for indicating K transmission configuration indicator, TCI, states, and K is a positive integer; and determining, by the terminal device, from the K TCI states, a TCI state used for the PDSCH transmission in the multiple time domain resource units according to at least one of following information: the number of code division multiplexing, CDM, groups to which an adopted demodulation reference signal, DMRS, port belongs, a configuration of PDSCH repetition transmission scheme, a configuration scheme for the number of the multiple time domain resource units, and a physical resource configuration in one time domain resource unit of the multiple time domain resource units, characterized in that K is a positive integer greater than 1, and determining, by the terminal device, from the K TCI states, the TCI state used for the PDSCH transmission in the multiple time domain resource units according to the number of CDM groups to which the adopted DMRS port belongs comprises: when the number of CDM groups to which the adopted DMRS port belongs is 1, determining, by the terminal device, that PDSCH transmission in each of the multiple time domain resource units uses one of the K TCI states, at least a part of the multiple time domain resource units using different TCI states; and when the number of CDM groups to which the adopted DMRS port belongs is greater than 1, determining, by the terminal device, that the PDSCH transmission in each of the multiple time domain resource units uses multiple TCI states among the K TCI states. receiving, by a terminal device, downlink control information, DCI, wherein the DCI is used for scheduling physical downlink shared channel, PDSCH, transmission in multiple time domain resource units, and the DCI is further used for indicating K transmission configuration indicator, TCI, states, and K is a positive integer; and determining, by the terminal device, from the K TCI states, a TCI state used for the PDSCH transmission in the multiple time domain resource units according to at least one of following information: the number of code division multiplexing, CDM, groups to which an adopted demodulation reference signal, DMRS, port belongs, a configuration of PDSCH repetition transmission scheme, a configuration scheme for the number of the multiple time domain resource units, and a physical resource configuration in one time domain resource unit of the multiple time domain resource units, characterized in that K is a positive integer greater than 1, and determining, by the terminal device, from the K TCI states, the TCI state used for the PDSCH transmission in the multiple time domain resource units according to the number of CDM groups to which the adopted DMRS port belongs comprises: when the number of CDM groups to which the adopted DMRS port belongs is 1, determining, by the terminal device, that PDSCH transmission in each of the multiple time domain resource units uses one of the K TCI states, at least a part of the multiple time domain resource units using different TCI states; and when the number of CDM groups to which the adopted DMRS port belongs is greater than 1, determining, by the terminal device, that the PDSCH transmission in each of the multiple time domain resource units uses multiple TCI states among the K TCI states. when the number of CDM groups to which the adopted DMRS port belongs is 1, determining, by the terminal device, that PDSCH transmission in each of the multiple time domain resource units uses one of the K TCI states, at least a part of the multiple time domain resource units using different TCI states; and when the number of CDM groups to which the adopted DMRS port belongs is greater than 1, determining, by the terminal device, that the PDSCH transmission in each of the multiple time domain resource units uses multiple TCI states among the K TCI states.