The present application relates to the technical field of communications, and discloses a data transmission method and apparatus, a device, and a storage medium. The present application provides a data transmission method: before sending a packet to be transmitted, a terminal device or an access network device determines a first object to which said packet belongs, and transmits said packet according to transmission requirements and/or a QoS parameter for the first object. Information about the transmission requirements and/or the QoS parameter for layers such as an application, a data stream, a QoS flow, an ADU, a frame, an encoding slice, and a unit set is given, thereby implementing QoS guarantee for the application, the data stream, the QoS flow, the ADU, the frame, the encoding slice, and the unit set, and satisfying reliability and delay requirements for the objects in the data transmission process.