Provided in embodiments of the present application are an uplink transmission method, terminal device and network device. The terminal device can mark a quality of service (QoS) flow mapped by data carried in a data radio bearer (DRB). The method comprises: a terminal device determining, according to a first mapping relationship, a marking form of a first quality of service (QoS) flow corresponding to a data packet carried in a first data radio bearer (DRB), the first mapping relationship being a mapping relationship between the QoS flow and the DRB; according to the marking form of the first QoS flow, marking the first QoS flow corresponding to the data packet carried in the first DRB; and transmitting the marked data packet through the first DRB to a network device.