A method for uplink transmission, comprising: determining, by a terminal device, according to first mapping relationships, an identification manner for a first Quality of Service, QoS, flow corresponding to a data packet carried in a first Data Radio Bearer, DRB, the first mapping relationships being mapping relationships between QoS flows and DRBs; wherein determining, by the terminal device, according to the first mapping relationships, the identification manner for the first QoS flow corresponding to the data packet carried in the first DRB comprises: when the QoS flows are in multiple-to-one correspondences with the DRBs in the first mapping relationships, determining, by the terminal device, the identification manner for the first QoS flow according to a number of QoS flows corresponding to one DRB, which comprises: when the number of QoS flows corresponding to each DRB is identical in the first mapping relationships or the numbers of QoS flows corresponding to at least two DRBs are different from each other in the first mapping relationships, determining, by the terminal device, the identification manner for the first QoS flow according to the number of QoS flows corresponding to the first DRB, which comprises: when the number of QoS flows corresponding to the first DRB is less than a first preset number threshold, determining that a second identification manner is adopted to identify the first QoS flow, the second identification manner being that identification information having a specific number of bits is determined according to the number of QoS flows corresponding to the first DRB, and the first QoS flow is identified by the identification information having the specific number of bits; when the number of QoS flows corresponding to the first DRB is greater than the first preset number threshold, determining that a third identification manner is adopted to identify the first QoS flow, the third identification manner being that the first QoS flow is identified by a QoS flow Identity, ID, of the first QoS flow; identifying, by the terminal device, according to the identification manner for the first QoS flow, the first QoS flow corresponding to the data packet carried in the first DRB; and sending, by the terminal device, the data packet comprising the identification information of the first QoS flow to a network device via the first DRB. determining, by a terminal device, according to first mapping relationships, an identification manner for a first Quality of Service, QoS, flow corresponding to a data packet carried in a first Data Radio Bearer, DRB, the first mapping relationships being mapping relationships between QoS flows and DRBs; wherein determining, by the terminal device, according to the first mapping relationships, the identification manner for the first QoS flow corresponding to the data packet carried in the first DRB comprises: when the QoS flows are in multiple-to-one correspondences with the DRBs in the first mapping relationships, determining, by the terminal device, the identification manner for the first QoS flow according to a number of QoS flows corresponding to one DRB, which comprises: when the number of QoS flows corresponding to each DRB is identical in the first mapping relationships or the numbers of QoS flows corresponding to at least two DRBs are different from each other in the first mapping relationships, determining, by the terminal device, the identification manner for the first QoS flow according to the number of QoS flows corresponding to the first DRB, which comprises: when the number of QoS flows corresponding to the first DRB is less than a first preset number threshold, determining that a second identification manner is adopted to identify the first QoS flow, the second identification manner being that identification information having a specific number of bits is determined according to the number of QoS flows corresponding to the first DRB, and the first QoS flow is identified by the identification information having the specific number of bits; when the number of QoS flows corresponding to the first DRB is greater than the first preset number threshold, determining that a third identification manner is adopted to identify the first QoS flow, the third identification manner being that the first QoS flow is identified by a QoS flow Identity, ID, of the first QoS flow; identifying, by the terminal device, according to the identification manner for the first QoS flow, the first QoS flow corresponding to the data packet carried in the first DRB; and sending, by the terminal device, the data packet comprising the identification information of the first QoS flow to a network device via the first DRB.