A data transmission method, comprising: receiving, by a terminal device, downlink control information, DCI, from a network device; determining, by the terminal device, a plurality of pieces of quasi-co-location, QCL, information based on the DCI, wherein the plurality of pieces of QCL information correspond to a plurality of time domain units, and each time domain unit corresponds to at least one piece of QCL information; wherein at least two of the plurality of pieces of QCL information are different; and receiving, by the terminal device, downlink data based on the plurality of pieces of QCL information from the network device; wherein the DCI comprises a plurality of pieces of transmission configuration indicator, TCI, indication information, each piece of TCI indication information is used to indicate one TCI state, and each TCI state comprises at least one of the plurality of pieces of QCL information; characterized in that the TCI state comprises first QCL information and second QCL information, the first QCL information comprises a first reference signal and a first QCL type, the second QCL information comprises a second reference signal and the first QCL type, the first reference signal is different from the second reference signal, the first reference signal and a first antenna port group satisfy a QCL relationship, and the second reference signal and a second antenna port group satisfy the QCL relationship, wherein the first QCL information further comprises a third reference signal and a second QCL type, the second QCL information further comprises a fourth reference signal and the second QCL type, the third reference signal is different from the fourth reference signal, the third reference signal and the first antenna port group satisfy the QCL relationship, and the fourth reference signal and the second antenna port group satisfy the QCL relationship, and wherein the first antenna port group and the second antenna port group are associated with a same time domain unit in the plurality of time domain units. receiving, by a terminal device, downlink control information, DCI, from a network device; determining, by the terminal device, a plurality of pieces of quasi-co-location, QCL, information based on the DCI, wherein the plurality of pieces of QCL information correspond to a plurality of time domain units, and each time domain unit corresponds to at least one piece of QCL information; wherein at least two of the plurality of pieces of QCL information are different; and receiving, by the terminal device, downlink data based on the plurality of pieces of QCL information from the network device; wherein the DCI comprises a plurality of pieces of transmission configuration indicator, TCI, indication information, each piece of TCI indication information is used to indicate one TCI state, and each TCI state comprises at least one of the plurality of pieces of QCL information; characterized in that the TCI state comprises first QCL information and second QCL information, the first QCL information comprises a first reference signal and a first QCL type, the second QCL information comprises a second reference signal and the first QCL type, the first reference signal is different from the second reference signal, the first reference signal and a first antenna port group satisfy a QCL relationship, and the second reference signal and a second antenna port group satisfy the QCL relationship, wherein the first QCL information further comprises a third reference signal and a second QCL type, the second QCL information further comprises a fourth reference signal and the second QCL type, the third reference signal is different from the fourth reference signal, the third reference signal and the first antenna port group satisfy the QCL relationship, and the fourth reference signal and the second antenna port group satisfy the QCL relationship, and wherein the first antenna port group and the second antenna port group are associated with a same time domain unit in the plurality of time domain units.